A bearing device for a wheel, comprising a bearing for a wheel comprising: an outer member having double-row outer raceway surfaces (13, 14) formed on an inner periphery thereof; an inner member comprising a hub wheel and an inner race, the inner member having double-row inner raceway surfaces (7, 8) formed on an outer periphery thereof so as to be opposed to the double-row outer raceway surfaces (13, 14); and double-row rolling elements (3, 4) interposed between the double-row outer raceway surfaces (13, 14) of the outer member and the double-row inner raceway surfaces (7, 8) of the inner member (1, 2), the bearing for a wheel having 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, wherein a plurality of convex portions extending in an axial direction are formed on one of the hub wheel and the stem section of the outer joint member, and the stem section of the outer joint member is press-fitted to the hub wheel, to thereby provide a convex and concave fitting structure in which the plurality of convex portions and a plurality of secondary concave portions formed on another of the hub wheel and the stem section of the outer joint member are brought into close contact with each other at an entire fitting contact portion therebetween, characterized in that the plurality of convex portions are press-fitted to a plurality of primary concave portions having an interference with respect to only circumferential side wall portions of each of the plurality of convex portions and formed on another of the hub wheel and the stem section of the outer joint member, and a shape of only the circumferential side wall portions of the each of the plurality of convex portions is transferred to the another of the hub wheel and the stem section of the outer joint member by accompanying cutting during the press-fitting, thereby forming the plurality of secondary concave portions. an outer member having double-row outer raceway surfaces (13, 14) formed on an inner periphery thereof; an inner member comprising a hub wheel and an inner race, the inner member having double-row inner raceway surfaces (7, 8) formed on an outer periphery thereof so as to be opposed to the double-row outer raceway surfaces (13, 14); and double-row rolling elements (3, 4) interposed between the double-row outer raceway surfaces (13, 14) of the outer member and the double-row inner raceway surfaces (7, 8) of the inner member (1, 2), the bearing for a wheel having 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, wherein a plurality of convex portions extending in an axial direction are formed on one of the hub wheel and the stem section of the outer joint member, and the stem section of the outer joint member is press-fitted to the hub wheel, to thereby provide a convex and concave fitting structure in which the plurality of convex portions and a plurality of secondary concave portions formed on another of the hub wheel and the stem section of the outer joint member are brought into close contact with each other at an entire fitting contact portion therebetween, characterized in that the plurality of convex portions are press-fitted to a plurality of primary concave portions having an interference with respect to only circumferential side wall portions of each of the plurality of convex portions and formed on another of the hub wheel and the stem section of the outer joint member, and a shape of only the circumferential side wall portions of the each of the plurality of convex portions is transferred to the another of the hub wheel and the stem section of the outer joint member by accompanying cutting during the press-fitting, thereby forming the plurality of secondary concave portions.