The motor controller includes: a current detection section that detects a current between a battery and an inverter circuit generating a voltage applied to a coil of a motor; an overload determination value output section that outputs an overload determination value used to determine whether or not the motor is overloaded; an overload determination section that compares a current value detected by the current detection section against the overload determination value, and that determines the motor to be overloaded in a case in which the current value detected by the current detection section is the overload determination value or greater; and a forced 500 rpm instruction section that controls the motor rotation speed to 500 rpm, this being a specific speed, in a case in which the overload determination section has determined the motor to be overloaded.