To provide a transistor inverter device quickly detecting abnormalities of short circuit or the like of a heating coil and surely preventing damage or the like of an inverter circuit.

The transistor inverter device is provided with a semiconductor system inverter circuit, an output transformer whose primary side is connected to an output side of the inverter circuit, and a heating coil connected to a secondary side of the out transformer. The transistor inverter circuit is so structured that a detecting transformer can be formed at the secondary side of the output transformer and a safety coil with an inductance smaller than that of the heating coil is connected in parallel with the heating coil, so that an overload on the inverter circuit is prevented by the safety coil at abnormalities of the heating coil.