To provide an improved type molecular resistance vacuum pump structure in the case when pumping speed and a compression ratio are not so important in comparison with lightening and miniaturization.

A vacuum pump device is furnished with a rotor, a motor to rotate the rotor around an axis of rotation as its center, a stator provided in the neighbourhood of the rotor and a housing to surround the rotor and the stator. The stator is furnished with at least one spiral groove having an opening facing against the rotor. An inlet to fluid-communicate to an inside part of the spiral groove is formed in the housing. When the motor rotates the rotor, gas is delivered outward to the axis of rotation through the spiral groove. The stator can be furnished with not less than two of the spiral grooves connected to each other in parallel. The spiral groove can be smaller on its cross-section from a large cross-section section of an inside part of the stator to a small cross-section of an outside part of the stator.