A control apparatus is applied to a system that includes a rotating electric machine and an inverter. The inverter has, for each of a plurality of phases, upper-arm and lower-arm switches each of which has a diode connected in antiparallel thereto. The control apparatus includes an all-phase short-circuiting unit and a single-phase short-circuiting unit. The all-phase short-circuiting unit performs all-phase short-circuit control of turning on, for example, all the upper-arm switches of the plurality of phases while turning off all the lower-arm switches of the plurality of phases. The single-phase short-circuiting unit performs, in a regenerative drive state of the rotating electric machine and prior to execution of the all-phase short-circuit control, single-phase short-circuit control of turning on one of the upper-arm and lower-arm switches of one of the plurality of phases, turning off the other switch of the phase and turning off all the switches of the remaining phases.