A control apparatus includes: a data acquisition part that is configured to acquire torque data indicating a drive torque of an electric motor, rotation number data indicating a rotation number of the electric motor, and DC voltage data indicating a DC voltage supplied to an inverter which supplies an AC current to the electric motor; a determination basis derivation part that is configured to derive a determination basis based on a drive efficiency of the electric motor by using the torque data, the rotation number data, and the DC voltage data; and a control method determination part that is configured to determine, based on the determination basis, which one of a one-pulse control and a pulse-width modulation control is employed as a control method of the inverter.