The present invention obtains a control device capable of preventing the accuracy of temperature estimation from degrading due to aging. The control device (10) is provided with a correction unit (13) for correcting at least one of a thermal resistance, a heat generation amount, and a heat capacity that are physical quanties describing a thermal circuit model (30-1) including the thermal circuit of a rotating electric machine (1). The correction unit (13) uses measurement information including a temperature (T31) or a heat flow (U32) corresponding to a measurement position at which a sensor unit (8) has performed a measurement in the rotating electric machine (1) to correct at least one of the thermal resistance, the heat generation amount, and the heat capacity corresponding to the measurement position.