The thrust slide bearing (1) has a synthetic resin bearing body (2) having a ring-shaped upper surface (5) that functions as a sliding surface, a ring-shaped metal plate (4) that is supported on the ring-shaped upper surface (5) to be freely rotatable relative to the bearing body (2), and a ring-shaped cover (3) disposed so as to cover the ring-shaped upper surface (5) and the ring-shaped metal plate (4). The ring-shaped metal plate (4) has an inner disc section (44) that is formed as a unit with an outer disc section (43) and is disposed in the through hole (25) of the ring-shaped cover (3). The inner disc section (44) also functions as a reinforcing part (rib) of the outer disc section (44). Thereby, the deformation of the thrust slide bearing (1)is prevented even when a large force is applied via the piston rod.