A vehicle seat to be installed in a vehicle such as an automobile has a seat cushion (seat part) and a seat back (backrest).
What is considered important about the above-mentioned vehicle seat is to give a sitter a sense of good fit. Under such circumstances, a seat which has been proposed comprises a seat back whose seat surface has a curved shape so as to be bulged along the sitter's shoulder blade in the vertical direction (see Patent Document 1). Since such seat mainly supports the elbow bones area, as well as the shoulder blades area, which have comparatively low variance depending on the difference in physical sizes of sitters, the seat can provide a good fit irrespective of the physical size of the sitter.