PURPOSE: To prevent local thermal deformation by arranging plural temperature sensors and cooling elements in a dotted shape in an air bearing, and controlling the respective cooling elements according to temperatures in respective places in the air bearing so that the temperatures in the respective places fall within a preset temperature range.

CONSTITUTION: Plural temperature sensors 36 to 39 and plural electronic cooling elements 31 to 34 are incorporated into an air bearing 10 having a cylindrical rotor 11 fixed to a rotary shaft and a stator 20 to rotatably support the rotor 11 by securing a space to pass gas supplied through an air passage 28 or the like between it and an outer peripheral surface of the rotor 11. The temperature distribution of the air bearing 10 is grasped by a computer according to output signals of the respective temperature sensors 36 to 39, and a heat absorbing quantity (= an electric current quantity supplied to the electronic cooling elements) of respective electronic cooling elements 31 to 34 is found, and the respective electronic cooling elements 31 to 34 are driven so as to absorb heat equivalent to this heat absorbing quantity. Thereby, local thermal deformation is prevented.