To provide a protector for a motor which secures the safety of a vehicle together with the protection of a circuit, by detecting the overcurrent of an electric motorcar.

In the drive circuit for a motor for driving an electric motorcar, this protector is equipped with a current detection means 12 which detects the current flowing to the power element of an inverter, and a current command means 7 which decides the current to be let flow to the motor 1 by the torque command or the speed command given from outside. In the case that current value detected by the current detection means 12 gets over a current value, this protector continues to restrain the current command value by the current command value 7 regardless of the torque command or the speed command given from outside. In case that the current value detected by the current detection means 17 falls under the prescribed current value, this returns it to the current command value by the torque command or speed command given from outside by the current command means.