To provide a motor controller capable of surely deciding an emergency such as an insertion or the like by using the number of revolutions of a motor converted into a torque value.

The motor controller 1 is so constituted that a voltage of a power source 21 is monitored, the number of revolutions of a motor is converted into the torque by a constant signal and memory data when it is equal to a rotational multiplier of the motor 5 and that the insertion control of the motor is made by using the torque data.