A disk drive device includes a hub, a base plate, and a bearing unit. The bearing unit includes a shaft housing member, joined to the hub, having a through-hole in the center, a shaft having a smaller diameter section and a larger diameter section, a radial dynamic pressure grooves, and a lubricant agent. The opening shape of bearing hole of the base plate is so formed as to be larger than the outer shape of the larger diameter section. In the bearing unit, the larger diameter section of the bearing unit is fixed by a hardening resin present between the bearing unit and the bearing hole.