A friction roller type speed increaser (100) includes a high speed side shaft (11), a ring roller (21), a low speed side shaft (13), at least one fixed roller (15), at least one movable roller, and a housing (23) that surrounds the rollers. A bearing unit (45) that includes a cylindrical bearing housing (51) into which the high speed side shaft (11) is inserted, bearings (53 and 55) on an inner circumferential portion of the bearing housing (51) which rotatably support the high speed side shaft (11), an oil seal (59) which is provided at one end portion of the bearing housing (51) and closes an inner space including the bearings is floating-supported such that the bearing unit can move in a radial direction of the high speed side shaft (11) in a unit accommodating section (47) formed in the housing (23).