To make an elevation driving source compact and low-priced by employing a structure in which the force of the elevation driving source acts efficiently for elevating a seat body.

An elevation mechanism 50 of a seat device for a vehicle according to the present invention includes: a fixed bracket 53 for elevation which is coupled to move up and down at a front-end position of a moving table 35; an elevation rail 55 which is fitted to the fixed bracket 53 for elevation to be slidable, and has its front-end part connected to a fixed bracket 43 for sliding to rotate upward and downward; a cam mechanism which raises the elevation rail 55 and fixed bracket 53 for elevation up to tilt positions for elevation through forward movement of the seat body; and an elevation driving source which makes the elevation rail 55 slide upward and downward with respect to the fixed bracket 53 for elevation.