To prevent deterioration of exhaust velocity even when a protection net is provided for preventing entering of foreign materials.

A vacuum pump P performs exhausting from a suction port 2P of a casing 2 to an exhaust port 1P by the rotation of rotational bodies arranged in the casing 2, such as turbo mechanisms 5Y, 6. A protection net 15 is sandwiched between a spacer 71 and the casing 2 at the end of the suction port 2P on the side of the turbo mechanism, for preventing foreign materials from entering the turbo mechanism, from the side of the suction port 2P. It is thus unnecessary to project a flange inward from the suction port 2P so as to attaching a protection net. A maximum diameter of the suction port 2P is secured, while deterioration of exhaust velocity is prevented.