A solid-state image sensor, comprising an image sensor chip including a pixel region where a plurality of pixels are arranged and a peripheral region arranged around the pixel region, and a fixing portion including a substrate which supports the image sensor chip and a joint portion which joins the substrate to an external base, wherein the peripheral region includes a first portion, and a second portion which is smaller in an amount of generated heat than the first portion, the substrate includes a first side and a second side, the first portion is arranged nearer the first side than the second side, the second portion is arranged nearer the second side than the first side, and the joint portion is arranged on the first side of the substrate.