A range image sensor capable of improving its aperture ratio and yielding a range image with a favorable S/N ratio is provided. A range image sensor RS has an imaging region constituted by a plurality of one-dimensionally arranged units on a semiconductor substrate 1 and yields a range image according to a charge amount issued from the units. One unit comprises a photoresponsive region; two pairs of third semiconductor regions 9a, 9b opposing each other while interposing a photogate electrode PG in the opposing direction of first and second longer sides L1, L2; first and second transfer electrodes TX1, TX2 disposed between the third semiconductor regions 9a, 9b and the photogate electrode PG; fourth semiconductor regions 11a, 11b arranged between the third semiconductor regions 9a, 9b such as to oppose each other while interposing the photogate electrode PG in the opposing direction of the first and second longer sides L1, L2; and third transfer electrodes TX3 disposed between the fourth semiconductor regions 11a, 11b and the photogate electrode PG.