The transfer window is an auxiliary equipment for preventing pollution in clean rooms. Mainly used for the transfer of small items between clean areas or between non clean areas, it is characterized by double door interlocking, effectively reducing the number of times workers enter the purification room to transport items and minimizing pollution to the clean area. This device is widely used in places that require air purification, such as micro technology, biological laboratories, pharmaceutical factories, hospitals, food processing industries, LCD, electronic factories, and so on.