To provide a vehicular power supply controller that maintains the electric energy of a battery to a specific value or more at the time of stopping the engine of a vehicle, while securing a user's convenience.

The vehicular power supply controller 1 measures an elapsed time from the time when a power supply state is turned ON, when the power supply state is turned ON at the time of stopping the engine of a vehicle, and changes the power supply state from the ON state to an ACC state when the elapsed time reaches a first time T1. Then, when the elapsed time reaches a second time T2, the power supply state is changed from the ACC state to an OFF state.