A solid-state image sensor includes an image sensing unit in which a plurality of pixels are arrayed, a plurality of readout units configured to read out signals from the image sensing unit, a detector configured to detect an occurrence of a latch-up in each of the plurality of readout units, and a controller configured to control power supply to the plurality of readout units. The plurality of readout units are configured to read out signals from a same pixel in the image sensing unit. The controller is configured to shut off power supply to at least part of a readout unit in which the occurrence of the latch-up has been detected out of the plurality of readout units and thereafter supply power to the at least part.