A control device for rotating electric machine, which controls a rotating electric machine as a charging electric generator, using an inverter circuit, the control device including: an energization amount generating unit for generating a first electric generation mode in which an energization amount for a field winding and an energization amount for an armature winding of the rotating electric machine are controlled and the inverter circuit is driven to perform electric generation, and a second electric generation mode in which an energization amount for the field winding is controlled to perform electric generation; and an energization signal generating unit for, on the basis of variation-related information relevant to variation in one of electric generation torque and electric generation current of the rotating electric machine, performing switching between the first electric generation mode and the second electric generation mode, and generating energization signals for the field winding and the armature winding.