A bearing device includes a bearing having an outer race with double-row outer raceway surfaces formed on its inner periphery, a hub wheel and an inner race having double-row inner raceway surfaces formed on outer peripheries thereof opposed to the outer raceway surfaces, and double-row rolling elements interposed between the outer and inner raceway surfaces. The bearing has a constant velocity universal joint separably coupled thereto with a screw fastening structure, in which a stem section of an outer joint member of the constant velocity universal joint is fitted to an inner diameter portion of the hub wheel, and in which a plurality of convex portions extending in an axial direction are formed on the stem section, and a plurality of concave portions having an interference with respect to only circumferential side wall portions of each of the plurality of convex portions are formed on the hub wheel.