To facilitate working and reduce cost in a hub unit for rotatably supporting the wheel of an automobile with the suspension device by providing a cylindrical member having double row outer ring raceway tracks, and a flange member formed with an outward flange, so as to form a hub.

This hub 2b is respectively provided with an outward flange 5b on the outer circumferential face, and double row outer ring raceway tracks 6, 6 on the inner circumferential face, and it is constituted by combination of a cylindrical member 12a and a flange member 13a. This cylindrical member 12a is nearly formed into a cylindrical shape by plastically working a metallic material such as carbon steel. The flange member 13a is constituted by combination of half pieces 14a, 14b of which each has L-section having a cylindrical part 17 and a circular ring part 18 and is formed into circular ring shape as a whole, by press working such as punching, bending (burning) and trimming of a metallic plate. The flange member 13a is exteriorly fitted to the cylindrical member 12a, so that one part of the cylindrical member 12a exists inside in the diametral direction of the outward flange 5b.