To reduce a cost and a size.

A high speed fluid device has a friction roller type speed-up gear A utilizing wedge action. The speed-up gear A comprises: a low speed side shaft 3 rotatably supported by a housing 1 and having an outer ring 32 fitted to one end part thereof; a high speed side shaft 17 rotatably supported by the housing to be eccentric from the outer ring 32; a guide roller 37a rotatably supported between the outer ring 32 and the high speed side shaft 17; and a movable roller. The high speed side shaft 17 is rotatably supported by the housing 2 through a rolling ball bearing 81 (angular contact ball bearing).