An image sensor able to capture an image with a suitable dynamic range even in a case where a bright/dark difference within an imaging range is large is provided. An image sensor 1 is provided with a substrate 2, a plurality of first photodiodes 5 arranged on the substrate 2 corresponding to a plurality of pixels 3, receiving light incident upon a first principal surface S1, and generating charges in accordance with the amounts of light received, and a plurality of second photodiodes 6 arranged at positions in behind side of the plurality of first photodiodes 5 corresponding to the plurality of pixels 3, receiving light incident upon the first principal surface S1 and passing through at least one of the plurality of first photodiodes 5 and the substrate 2, and generating charges in accordance with amounts of light received. Electric signals based on charges generated in the plurality of second photodiodes 6 of the same pixels are added to electric signals based on charges generated in the plurality of first photodiodes 5.