A rotary damper (1) has a first sealing ring (8a) and a first bushing (4a) which are located between a through-hole (23) of a circular cylindrical chamber (21) inside a case (2) and a lower end part (33a) of a rotor body (31) of a rotor (3), and a second sealing ring (8b) and a second bushing (4b) which are located between a through-hole (60) in a lid (6) and an upper end part (33b) of the rotor body (31). The first sealing ring (8a) has an outer peripheral surface (85) having a width in a direction of a center axis of the circular cylindrical chamber (21) and being pressed against an inner peripheral surface (220) of the through-hole (23), and an inner peripheral surface (84) having a width in the direction of the center axis of the circular cylindrical chamber (21) and being pressed against an outer peripheral surface (34) of the lower end part (33a), and the second sealing ring (8b) has an outer peripheral surface (85) having a width in the direction of the center axis of the circular cylindrical chamber (21) and being pressed against an inner peripheral surface (64) of the through-hole 961 (60), and an inner peripheral surface (84) having a width in the direction of the center axis of the circular cylindrical chamber (21) and being pressed against the outer peripheral surface (34) of the upper end part (33b).