A temperature abnormality of the power module is accurately detected. A power conversion device including a power semiconductor module with a switching element, includes: a gate driver circuit configured to drive a switching element and transmitting a response signal upon a switching operation of the switching element; a control unit device configured to output to a gate driver circuit an instruction signal for switching; a temperature detection unit configured to calculate a bonding temperature of the switching element based on a response signal to the instruction signal; and a calculation unit configured to determine a state of a power semiconductor module according to a bonding temperature calculated by the temperature detection unit and the response signal.