A configuration that can increase the reliability of a backup operation is realized in a simpler manner. An in-vehicle backup power source control apparatus includes a first control unit that causes a charge/discharge unit (first discharge unit) to perform a first discharge operation when power supply that is based on a power source unit enters a failure state, and a second control unit that causes a second discharge unit to perform a second discharge operation when power supply that is based on the power source unit enters a failure state and at least the first discharge operation performed by the charge/discharge unit is in an abnormal state.