To quickly stop motors to abnormal operation by a person by arranging a detecting means for detecting the rotational direction of driving motors in a passage up to a stool seat and a stool cover from output shafts of the driving motors, and stopping the driving motors when the driving motors do not rotate in the same direction as the driving direction.

A stool seat driving motor 22 and a stool cover driving motor 23 rotate by a signal from the control part, and this rotation is transmitted to a stool seat (and/or a stool cover) through a transmitting means composed of a gear train to open/close the closet seat. In this case, multipolar magnetizing magnets 21 are installed on output shafts of the respective driving motors 22, 23, and MR elements 20 are arranged in relative positions of the respective magnets 21. Two-phase signals from the respective MR elements 20 are outputted according to rotation of the motors 22, 23, and a phase of the signals is monitored by the control part to detect the rotational direction. The control part monitors whether or not the motor rotating direction is the same as a driving command of the motors, and when the motor rotating direction is not the same as the driving command of the motors, driving of the respective motors 22, 23 is stopped.