A motor-driven compressor includes an electric motor driven by a motor driver, which includes a switching element that converts DC voltage from a battery to AC voltage. A control unit controls the switching operation of the switching element. A temperature detector detects the temperature of the switching element. The control unit suspends the switching operation of the switching element when the temperature detected by the temperature detector rises to a temperature threshold. The temperature threshold includes a first temperature threshold, corresponding to a withstand temperature of the switching element, and a second temperature threshold, which is higher than the first temperature threshold. The control unit switches the temperature threshold from the first temperature threshold to the second temperature threshold when the control unit activates a field weakening control that reduces counter electromotive force generated by the electric motor.