To provide a bearing device which can inhibit preload change in a bearing 31 which occurs in conjunction with temperature rise of the bearing 31 and a rotary shaft 10.SOLUTION: An outer spacer cooling structure cools only an outer spacer 33 to cause a temperature difference between an inner spacer 32 and the outer spacer 33. An inner ring 37 of a bearing 31 is displaced relative to an outer ring 38 in a direction such that a preload in the bearing 31 is reduced according to the temperature difference.SELECTED DRAWING: Figure 5