PURPOSE: To provide a vacuum pump furnished with a suction filter suitable for separating particulates having a large permeation value and of a particle size of more than about 1 μ by forming the filter as a filter fleece 18 made of high class steel fiber.

CONSTITUTION: A filter is formed as a filter fleece 18 made of high class steel fiber and the high class steel fiber is made at least 4 μ thick. Additionally, the filter is formed as a metal fiber fleece of 1-3 mm thick which is sintered having weight of about 800-1000 g/m2 and porosity of more than 90%. The filter fleece 18 is clamped between a flange 8 and a flange 11, and a range of the filter fleece 18 is certainly sealed by a seal ring 19 surrounding the filter fleece 18. The flange 11 is a constitutional member of an outlet pipe 12 of a rough filter 13, and the rough filter 13 is formed in a siphon shape of a central pipe part 14 and a easing 15 on the outside.