To provide a thrust dynamic pressure gas bearing capable of eliminating the adjustment of a several microns of clearance by an advanced assembly technique required for an assembly and an adjustment by assuring the formation of a gas film for the thrust dynamic gas pressure bearing to prevent a reduction in an allowable load.

In this thrust dynamic pressure gas bearing 14A, a bearing surface is divided into eight parts with eight recessed parts 5A.A tapered part 6A is formed on one side of each recessed part 5A, and a wear resistant film 8A is formed on each bearing surface.Recessed parts 13 are disposed on the rear surfaces of the divided bearing surfaces so as to be disposed alternately with the bearing surface side recessed parts 5A, and a thin-walled part 12A is formed thereon.Also a leaf spring 10 is installed at a projected part 7 positioned at the rear of the recessed part 5A and between the adjacent recessed parts 13 in the clearance thereof from a housing surface.As a result, the fittability of the bearing can be improved by the interaction between the thin-walled part 12A and the leaf spring 10 to form an excellent gas film so as to produce a dynamic pressure.