A vehicular power supply apparatus includes: a first port to which an electric load is connected; a second port to which a first storage apparatus is connected; a third port to which a second storage apparatus is connected; a fourth port to which a power generation apparatus is connected; a first switch disposed between the first and second ports; a second switch disposed between the second and fourth ports; a third switch disposed between the first and third ports; a fourth switch disposed between the third and fourth ports; and a condition switching unit configured to switch between a first condition in which the first and fourth switches are conductive, the second and third switches are cut off, and a second condition in which the first sand fourth switches are cut off, the second and the switches are conductive.