Forty years has passed after the promulgation of the Industrial Safety and Health Law, Japan. In this paper, working environmental control based on the law was overviewed. The working environmental control includes evaluation and engineering controls of hazardous elements in the work environment. It is an important task for industrial physicians to conduct, similar to workers' health control. The annual cycle of evaluation and engineering control for environments is also similar to the cycle of diagnosis and clinical treatment for workers for the workers' health control. Historically, the working environmental control system was based on a list of worksites, using chemicals listed in the regulations, and the concentration of contaminants in the air at each work site. Recently, control banding of newly developed chemicals without administrative control levels, was introduced as a method for the working environmental control.