To provide a seat device for automobile which has a comparatively simple construction to be materialized inexpensively, and the construction which can switch over the position of an ottoman from working position to stowed position with a non-maneuvering system.

A seat cushion 11 is adjustable to slide back and forth by a sliding mechanism 16 and at the same time an ottoman 19, which is movable in a tilting up and down directions, is installed to the front end side of the seat cushion 11. Then, the ottoman 19 is equipped with an ottoman tilting mechanism 20 (for instance, a mechanism which comprises a cam face 32 and a cam follower 28 placed between the side of a frame 22 of the ottoman 19 and the side of a leg base 15 supporting the seat cushion 11).