Abstract: There is disclosed an automotive differential device for transferring a rotational drive force from an automotive engine to a drive axle. This differential device includes: a differential gear mechanism equipped with a pair of side gears, three pinions meshing with the side gears, three pinion shafts pivotably supporting the three pinions, and a shaft supporting member supporting inner ends of the three pinion shafts; and a case member with an integral structure housing the differential gear mechanism. This case member includes a flange section receiving the rotational drive force by way of a ring gear, and a plurality of openings for mounting the side gears and pinions. The three pinions are oriented so that their axes form 120 degree phase angles, and the three openings are formed at three equidistant positions along the perimeter wall section of the case member.