THRUST SLIDING BEARING

A thrust sliding bearing (1) includes an upper casing (10) having a polyacetal resin-made flat annular surface (2) and a lower casing (20) superposed on the upper casing (10) so as to be rotatable about an axis (O) of the upper casing (10) and having a polyacetal resin-made annular surface (3) opposing the annular surface (2) of the upper casing (10).