In a disk drive device, a magnetic recording disk is to be mounted on a hub. A base plate rotatably supports the hub through a bearing unit. A laminated core is formed by laminating magnetic steel sheets, the laminated core having a ring portion and a plurality of teeth that extend radially from the ring portion, with coils wound around the plurality of teeth. A projecting portion is formed along the bearing unit, which axially extends toward the inner surface of the hub and by which the core is supported. The laminated core is fixed by sandwiching the ring portion between a seat formed on the base and an extending portion extending radially outward from the projecting portion.