To provide a controller for a robot, capable of reducing the moving amount of a servo motor from the generation of a state to stop the rotation of the servo motor to the stop of the rotation of the servo motor without limiting (reducing) the rotational speed of the servo motor.

When a power source of a servo motor 15 is turned off or when an emergency switch 23 is turned on, an electric signal is given to a pulse oscillator 11 and a deviation counter 12 by an electric circuit constituted of a power source monitor relay 21, transistors 22, 24, an emergency stop switch 23, an OR circuit 26, a DC power source of 24 V for control, and a GND, supply of a pulse signal for commanding the rotational angle of the servo motor 15 is stopped, an accumulated pulse of the deviation counter 12 is cleared, and the rotation of the servo motor 15 is stopped.