This article deals with the system of working environment measurement under Industrial Safety & Health Act which is to assure safe and healthful working condition for workers, the system of working environment measurement is very important to prevent industrial accidents, especially vocational disease caused by hazardous objects. After execution of working environment measurement, the result of measurement would be analyzed and then proper actions should be taken by company in proportion to the exposure level of hazardous objects, for example, change of working process or form, in order to protect workers` health. In the meaning of foregoing, the system of working environment measurement under Industrial Safety & Health Act, plays a serious role in the field of industry, however, the range of its function could be somewhat wider. Nowadays, it is considered that prevention of environmental infringement is much more meaningful than late remedy. From this point new paradigm of WEM starts, and it will be helpful to achieve the social goal to reduce the environmental damage. To stand on this humble opinion, the asbestos exposure in Seoul subway station is argued on in this article.