To provide a hydrostatic gas bearing spindle that can limit changes in a position of a fitting surface.

The hydrostatic gas bearing spindle that is affixed to a mounting surface (PS) is provided with: a pivot (1) having the fitting surface (1a) on an end face; a housing (2) that surrounds the outer circumferential surface of the pivot (1) with a bearing clearance (10), into which a bearing gas for rotatably supporting the pivot (1) is supplied, therebetween; and first fixing boards (3) and second fixing boards (4) that are disposed at a distance from each other in the direction of the axial line (AX) of the housing (2) and are for fixing the housing (2) to the mounting surface (PS). The second fixing boards (4), which are disposed at positions that are farther from the fitting surface (1a) than the first fixing boards (3), comprise a linear guide mechanism (5) that is capable of linear guidance in the axial direction (AX).