A rotating device includes a hub on which a magnetic recording disk is to be mounted, and a base that supports the hub in a freely rotatable manner. When at least either one of the base and the hub is referred to as a work-piece, a method for manufacturing the rotating device includes a forming step for forming the work-piece, a blowing step for blowing the formed work-piece with solid grains, a cleaning step for cleaning the work-piece blown by the grains using a cleaning fluid, an assembling step for assembling the rotating device using the cleaned work-piece. The grains have a property of vaporizing in the cleaning step or being soluble with the cleaning fluid therein.