Occupational Health and Safety known as Kesehatan dan Keselamatan Kerja (K3) is one of actions to provide safe and healthy workplace which is free from enviromental poluution, so that is could reduce the risk of work accident, and it improves the work producticity. The aim of this research is to know how far the implementaion of Occupational Health and Safety in MAN 2 Kota Semarang. The researcher used observation and interview method, which involved some of science student. The researcher also distributed questionnaire and interviewed chemistry teacher. The researcher took 126 student from four classes as research