A robot apparatus according to one aspect of the present disclosure includes a robot body and a transfer leg for transferring the robot body. The robot body includes a robot arm mechanism and a sensor device for detecting an external force applied to the robot arm mechanism. The sensor device includes a sensor bottom plate to be installed on a robot installation table, a sensor top plate attached to the bottom surface of a base of the robot arm mechanism, and a sensor body for detecting the displacement between the sensor bottom plate and the sensor top plate. The transfer leg is configured to be able to fix the base or the sensor top plate to a transfer table in such a manner as to prevent the sensor bottom plate from coming into contact with the transfer table.