This paper suggests that a conceptual design of tool changer can exchange the end of arm tools (EOAT) of the developing rescue and relief robots. The target EOATs are paddle to rescue casualties and gripper for artillery shells. The proposed tool changer consists of two parts such as upper and lower part. Each part has its own mechanism with electronics. Upper and lower part rigidly attaches the robot arm and EOAT, respectively. The rotating shaft equipped on the upper part can move linearly back and forth in order to couple or decouple the lower part from the upper part. Lower and upper part electrically connects by the spring pin arrays attached at each part. The tool changer is to easily attach or detach EOATs to the robot arm with simple structure.