Abstract: A vacuum pump producing ultra high vacua has a housing containing a first set of rotor blades provided around a first rotor for producing ultra high vacua and a second set of rotor blades provided around a second rotor for producing low to high vacua wherein the first rotor and the second rotor are magnetically suspended during pump operation. The first rotor is disconnected from the second rotor during pump operation in a low to high vacuum range, and it is connected with the second rotor as the pump operation shifts from a high vacuum range to an ultra high vacuum range. Because of this feature, the pump operation ranging from a low vacuum range up to an ultra high vacuum range can be performed by a single pump.