To provide, with a simple structure an inverter device capable of protecting a switching element and a motor winding from being overheated, and helping a user recognize the restrictions on the motor output.

Voltage Vti corresponding to the detected temperature by the temperature detector 20 disposed near switching element 8 to 13 and voltage Vtm corresponding to the detected temperature by the temperature detector 27 fixed on a stator winding 25v are inputted into an amplifying circuit 35, and the voltage whose detected temperature is higher is invert-amplified. A comparison circuit 34 compares the amplified voltage with the voltage Vi corresponding to the detected current outputted from a current detector 7, and the commutating signals of switching elements 8 to 10 are masked in accordance with the comparative signal Sa. Therefore, the higher the detected temperature is, the smaller the restriction value of motor current is set. When motor current is restricted, a light emitting diode 47 is lit. When detected temperature exceed a prescribed value, fan motors 21a to 23a and 28a are driven.