In a housing 13, an air discharge hole 41 and a suction pipe 51 are arranged vertically in parallel and are located outward with respect to a bearing 12 that supports a vertical main spindle 11. A communication hole 43 connects between a space formed below the bearing 12 and an intermediate portion of the air discharge hole 41 in a height direction. A bottom end of the air discharge hole 41 and that of the suction pipe 51 communicate with an oil reservoir 45. Lubricant in the oil reservoir 45 is sucked through the suction pipe 51 and is recovered at a position outside the housing 13.