Abstract: A seat for a special vehicle, includes a seat back, a seat cushion, and a pair of elongated stays for interconnecting the seat back and the seat cushion. The seat back includes a back frame, a first cushioned padding having lower and upper sections, the lower section having bulged portions formed at its left and right side portions by bulging the left and right side portions to a relatively large degree in a manner to allow the lower section to have a substantially C-shape in cross section, and a first covering sheet covering the first cushioned padding therethrough, the first cushioned padding, covered with the first covering sheet, being attached to the back frame.