A shaft rotates in a housing on two single row tapered roller bearings mounted in opposition such that the raceways of the one bearing taper downwardly toward the raceways of the other bearing. An intake port sucks the air of an underfloor chamber, a fan supplies the air to an upper part in the apparatus, and a blowoff port is installed on a side surface of an upper-floor part of the apparatus for supplying the air into the clean room. The FPMs utilize resident applications to process data received from the NPMs.