A power conversion apparatus comprising: a power semiconductor module having one pair or pairs of semiconductor switching devices (Q1-Q6) which are connected in series to form one half-bridge circuit or half-bridge circuits and which are driven to be ON/OFF while being associated with one another, and a plurality of flywheel diodes (D1-D6) back-to-back connected to the semiconductor switching devices (Q1-Q6) respectively; a control circuit which drives the semiconductor switching devices (Q1-Q6) to be ON/OFF respectively; current detection circuits (11a-11f; 17a-17f) which detect currents flowing in the half-bridge circuits through current detection terminals provided in ones of the semiconductor switching devices (Q1-Q6) forming the half-bridge circuits in the power semiconductor module and current detection terminals provided in the flywheel diodes (D1-D6) back-to-back connected to the ones of the semiconductor switching devices (Q1-Q6); sample-and-hold circuits (14a-14c) which hold voltages corresponding to the currents detected through the current detection circuits (11a-11f; 17a-17f) for a predetermined period of time; said power conversion apparatus characterised in that the control circuit is provided to be separately isolated from the power semiconductor module; said power conversion apparatus further comprises insulating circuits (13a-13c) which transmit the voltages held by the sample-and-hold circuits (14a-14c) to the control circuit; and voltage regulation circuits (16a-16c) for regulating gains and offsets of the voltage signals given from the sample-and-hold circuits (14a-14c) through the insulating circuits (13a-13c) before they are inputted to the control circuit. a power semiconductor module having one pair or pairs of semiconductor switching devices (Q1-Q6) which are connected in series to form one half-bridge circuit or half-bridge circuits and which are driven to be ON/OFF while being associated with one another, and a plurality of flywheel diodes (D1-D6) back-to-back connected to the semiconductor switching devices (Q1-Q6) respectively; a control circuit which drives the semiconductor switching devices (Q1-Q6) to be ON/OFF respectively; current detection circuits (11a-11f; 17a-17f) which detect currents flowing in the half-bridge circuits through current detection terminals provided in ones of the semiconductor switching devices (Q1-Q6) forming the half-bridge circuits in the power semiconductor module and current detection terminals provided in the flywheel diodes (D1-D6) back-to-back connected to the ones of the semiconductor switching devices (Q1-Q6); sample-and-hold circuits (14a-14c) which hold voltages corresponding to the currents detected through the current detection circuits (11a-11f; 17a-17f) for a predetermined period of time; said power conversion apparatus characterised in that the control circuit is provided to be separately isolated from the power semiconductor module; said power conversion apparatus further comprises insulating circuits (13a-13c) which transmit the voltages held by the sample-and-hold circuits (14a-14c) to the control circuit; and voltage regulation circuits (16a-16c) for regulating gains and offsets of the voltage signals given from the sample-and-hold circuits (14a-14c) through the insulating circuits (13a-13c) before they are inputted to the control circuit.