An in-vehicle backup control apparatus includes a discharge circuit that discharges a power storage unit and a control unit that controls the discharge circuit. The control unit sets either one of a superimposable voltage or a supply completion voltage as an interruption threshold value, the superimposable voltage being set as a voltage condition of the power storage unit when electric power is supplied simultaneously to a plurality of target loads during an abnormal state, and the supply completion voltage being set in association with one of the plurality of target loads. The control unit interrupts or delays the supply of electric power to the one of the plurality of target loads to prohibit the plurality of target loads from simultaneously operating if a charge voltage of the power storage unit reaches a value less than or equal to the interruption threshold value during the abnormal state.