;In recent years, with the continuous development of high-tech industry and constant advancement of process technologies, the new processes and new chemicals used in the semi-conductor plants are getting more complicated and dangerous. Thus, the safety and health operation management and emergency response of the unexpected accident in the plant require more manpower and resource to guarantee the safety in the plant area and reduce the probability of the unexpected disaster and accident occurrence. That is why the Emergency Response Team (ERT) is set up in the plant to respond to the disaster and accident, and perform first-aid and the related operations. Besides guaranteeing the plant safety and preventing the unexpected disasters and accidents, the attendance of ERT members will also indirectly affect their working efficiency and disaster recovery operation in the safety maintenance. Currently the ERT members work in three shifts system. Moreover, the semi-conductor plants are mostly in 24-hour operation. In terms of the manpower assignment, the managers mostly make decision based on the experience, and carry out manual scheduling operation. This deficient method fails to achieve the fair principle, and consumes much time in operation. For above issues, the study takes a semi-conductor plant located in Hsinchu Science Park as an example, by which the model developed in the study is proven to be reasonable and practical. It constructs a mathematic optimization model and calculates solution by using LINGO-9.0 software package. In this way, it works out the most even attendance schedule and manpower assignment optimization for the ERT members. The study results show the model developed in the study is more efficient than the manual assignment based on experience, which also achieves the fairness in the attendance schedule. It can provide reference for the high-tech plants in the practice of ERT manpower assignment.