To provide load supporting structure and a load supporting unit capable of equalizing clearance of sliding faces between an upper material and a lower material, in which load acts, and also capable of decreasing sliding resistance, by means of coaction between pressurized fluid supplied to an auxiliary hydrostatic pocket in which the auxiliary hydrostatic pocket is provided in the outer side of a main load retaining pocket and pressurized fluid supplied to the main load supporting pocket.

In the load supporting structure comprised of the upper material, the lower material supporting the upper material, and a fluid pressure supplying unit supplying fluid having designated pressure between a face of the upper material and a face of the lower material which are opposed each other, a circular groove in which a circular seal member is inserted is formed in one of faces of the upper and lower material, and the upper and lower material are relatively supported to a horizontal direction in a freely movable state via pressurized fluid supplying to the main load supporting pocket that is formed in the inner side of the seal member by the fluid pressure supplying unit. Specifically, the auxiliary hydrostatic pocket in which pressurized fluid is supplied is arranged in the outer side of the main load supporting pocket.