To provide a feed stage for an optical master disk exposing device which realizes highly accurate feeding, and also to provide its control device.

A base 90 disposed on a servo mounter by air pressure is provided with columns 89 that are separated in the feeding direction and in the orthogonal direction and of which one side ends are fixed to the base 90. The other side ends of the columns 89 are fixed to a moving body 13 via a rolling bearing 114 having a sphere, a cylindrical roller, or the like in the feeding direction at its upper end. The moving body 13 is fixed to an air spindle 19 that fixes a turn table 18 in its upper part and is statically floated in the radial or thrust direction by compressed air supplied from the outside (not shown). The air spindle 19 is fixed to an optical rotary encoder 21 generally constituted by A-phase and B-phase pulses having an several thousands of outputs in one circle and a Z-phase pulse occurring once in one circle via rotation driving motor 20. The rotary encoder 21 is rotatable by a communication signal from the outside (not shown) to the rotation driving motor 20.