A solid-state image sensor (100) is provided that includes a semiconductor substrate (500), a charge accumulator disposed in the semiconductor substrate (500) and configured to accumulate charge, a photoelectric converter (200) provided above the semiconductor substrate (500) and configured to convert light to charge, and a through electrode (600) passing through the semiconductor substrate (500) and electrically connecting the charge accumulator with the photoelectric converter (200). At an end portion on the photoelectric converter side of the through electrode (600), a cross-sectional area of a conductor (602) positioned at the center of the through electrode (600) in a cut section orthogonal to a through direction of the through electrode (600) gradually increases toward the photoelectric converter along the through direction.