A thrust sliding bearing 1 includes a synthetic resin-made bearing body 4 having an annular upper surface 2 and an annular outer peripheral surface 3; a synthetic resin-made bearing body 6 which is superposed on the bearing body 4 so as to be relatively rotatable; a synthetic resin-made thrust sliding bearing piece 7 interposed between the annular upper surface 2 of the bearing body 4 and an annular lower surface 5 of the bearing body 6; an annular upper cover 10 having an annular engaging inner peripheral surface 9 which engages an annular engaging outer peripheral surface 8 of the bearing body 4; and an annular metal plate 15 interposed between an annular upper surface 11 of the bearing body 6 and a lower surface 14 of the annular upper cover 10.