An image pickup apparatus includes a flexible substrate, the flexible substrate includes a plurality of functional regions segmented by bending portions, one of the functional regions is an image pickup device mounting region, one of the functional regions is at least two electronic component mounting regions folded at the bending portions, and one of the functional regions is at least one wiring region provided between the adjacent mounting regions of the flexible substrate, the image pickup device mounting region has a largest surface shape among the plurality of functional regions, and the plurality of functional regions decrease in length of each of at least paired opposing sides of each surface shape, in a stepwise manner as a distance from the image pickup device mounting region increases.