An electric power conversion apparatus converts electric power supplied to a motor having a winding set formed of coils corresponding to a plurality of phases. An inverter part has a plurality of FETs forming switching element pairs, each of which corresponds to each phase of the winding set. Pull-up resistors are provided between the coils and a high-potential side of a battery, respectively. A neutral point voltage detection part detects a neutral point voltage of the winding set. A microcomputer detects abnormality based on the neutral point voltage.