Tokyo Ohka Kogyo Co., Ltd. (TOK) provides chemical products, such as photoresist, and equipment needed to manufacture semiconductors and flat panel displays (FPD).

1936 April	:	Started as TOKYO OHKA RESEARCH LABORATORY.
1940 October	:	Reorganized as a joint-stock company, TOKYO OHKA KOGYO CO., LTD.
1967 January	:	SAGAMI PLANT (present SAGAMI OPERATION CENTER) began operations.

1980 November	:	Held the 1st TOKYO OHKA SEMINAR (semiconductor technology seminar).
1981 June	:	UTSUNOMIYA PLANT (our first full-scale mass production plant for photoresists used in semiconductor manufacturing) began operations.
1983 February	:	SAGAMI SECOND PLANT (present SHONAN TECHNICAL CENTER) began operations.
December	:	KUMAGAYA PLANT (plant for manufacturing industrial chemicals) began operations.
1984 January	:	YAMANASHI PLANT (exclusive plant for manufacturing photopolymer printing plates) began operations.
October	:	PROCESS EQUIPMENT PLANT (within SAGAMI SECOND PLANT / present SHONAN TECHNICAL CENTER) began operations.
December	:	ASO PLANT began operations.
1986 July	:	Listed in the Second Section of Tokyo Stock Exchange.
1987 March	:	Established OHKA AMERICA, INC. in California, U.S.
June	:	GOTEMBA PLANT began operations.
September	:	Established OHKA (UK) LTD. (present OHKA EUROPE LTD.).
1989 April	:	Established T.O.K. INTERNATIONAL, INC. in Oregon, U.S.
October	:	IKUNO PLANT began operations.
November	:	Held the 10th TOKYO OHKA SEMINAR.

1990 September	:	Listed in the First Section of Tokyo Stock Exchange.
November	:	Held the 1st TOKYO OHKA SEMINAR in Korea.
1992 October	:	Established TOK ENGINEERING CO., LTD.
December	:	Merged OHKA AMERICA, INC. and T.O.K. INTERNATIONAL, INC. (OHKA AMERICA, INC. / present TOKYO OHKA KOGYO AMERICA, INC.).
1993 May	:	OREGON PLANT of OHKA AMERICA, INC. (present TOKYO OHKA KOGYO AMERICA, INC.) began operations.
1994 February	:	KORIYAMA PLANT began operations.
May	:	Held the 1st TOKYO OHKA SEMINAR in Taiwan.
1995 May	:	Established TOK ITALIA S.p.A.

1996 July	:	Acquired ISO 9002 registration for GOTEMBA PLANT and SAGAMI OPERATION CENTER.
October	:	Dry Film Resist plant of TOK ITALIA S.p.A. began operations.
1997 February	:	Completed construction of new research building in SAGAMI OPERATION CENTER.
March	:	Established TOK TECHNO SERVICE CO., LTD.
May	:	Completed construction of our first oversea photoresist manufacturing plant for semiconductor fabrication at OREGON PLANT of OHKA AMERICA, INC.
December	:	Completed the third phase construction (manufacturing plant of photoresists for deep-UV) of KORIYAMA PLANT, and started the manufacture.
1998 January	:	Established TOK TAIWAN CO., LTD.
April	:	Completed construction of new research building in SHONAN PLANT (present SHONAN TECHNICAL CENTER).
1999 May	:	Acquired ISO 9002 registration for all the plants of Manufacturing Department.
November	:	Held the 20th TOKYO OHKA SEMINAR.
	:	Stripper / thinner manufacturing plant of TOK TAIWAN CO., LTD. began operations.
	:	Acquired ISO 14001 registration for KORIYAMA, UTSUNOMIYA and GOTEMBA PLANT.

2000 August	:	Completed construction (July) of the new headquarters building at the site that its Kawasaki Plant had used to stand, and has moved to the new headquarters.
2001 February	:	Developed TARF-P series (High-resolution, positive type photoresist for ArF excimer lasers).
March	:	Developed DELS series (Dielectric Layer sheet for PDP).
October	:	Completed construction of ELASLON manufacturing line in YAMANASHI PLANT.
December	:	Developed TELR-P series (Positive type photoresist for Organic EL Display).
2002 March	:	Developed TR63000 (Large square substrate coater / Developer system).
	:	Developed OEBR-CAN021 (Negative type photoresist for electron beams).
August	:	Established SINGAPORE REPRESENTATIVE OFFICE.
	:	Completed construction of PDP manufacturing material production plant in KORIYAMA PLANT.
October	:	Established SHANGHAI REPRESENTATIVE OFFICE.
2003 February	:	Completed construction of new research building in SAGAMI OPERATION CENTER.
October	:	SEOUL MARKETING OFFICE began operations.
November	:	DISTRIBUTION CONTROL CENTER began operations.
December	:	Developed TMMR (Permanent photoresist for MEMS).
2004 September	:	Established TOK KOREA CO., LTD.
October	:	Established CHANG CHUN TOK (CHANGSHU) CO., LTD.
2005 December	:	Established TOKYO OHKA KOGYO EUROPE B.V.
2006 January	:	OHKA AMERICA, INC. has changed its name to TOKYO OHKA KOGYO AMERICA, INC.
February	:	OHKA EUROPE LTD. has transferred all its business to TOKYO OHKA KOGYO EUROPE B.V.
	:	Completed construction of new research building in SAGAMI OPERATION CENTER.
2007 April	:	Completed construction of new research building in SAGAMI OPERATION CENTER.
2008 March	:	Completed construction of office building in Aso Pant.
2008 November	:	Developed TWM/TWR series （wafer handling system for processing through-silicon vias）.
2008 December	:	Developed TR165000FC series（float coating system）.
2009 April	:	Completed construction of stripping solution manufacturing plant in TOKYO OHKA KOGYO AMERICA, INC.（Oregon Plant）.
June	:	Developed EPLUS（diffusion source for photovoltaic）.
2011 January	:	Newly organized Marketing Division, Marketing Department.
June	:	Newly organized New Business Development Division, New Business Development Department.
November	:	Built a new production line of semiconductor photoresist in Koriyama plant.