A robot controller for avoiding an emergency stop of a robot due to shortage of the amount of charge of a secondary battery of a portable operating part during automatic operation of the robot. The robot controller includes a portable operating part having a secondary battery, a robot control part capable of communicating with the portable operating part and having a means for bringing the robot to an emergency stop when communication between the robot control part and the portable operating part is interrupted, a charging circuit for charging the secondary battery, and a cable for electrically connecting the charging circuit to the control part during automatic operation of the robot.