A bearing device for a wheel, comprising: an outer member having double-row outer raceway surfaces (26, 27), an inner member (1, 24) having double-row inner raceway surfaces (28, 29), rolling elements in double rows interposed between the double-row outer raceway surfaces of the outer member and the double-row inner raceway surfaces (26, 27) of the inner member (1, 24), and an outer joint member having a shaft section, wherein the inner member (1, 24) has a hub having a hole and a flange for attachment to a wheel, and wherein the shaft section of the outer joint member is inserted into the hole of the hub and is coupled to the hub, wherein an axially extending projection provided on an outer diameter surface of the shaft section of the outer joint member is press-fitted along the axial direction into a small recess provided on an inner diameter surface of the hole of the hub, characterized in that a recess is formed in the hole of the hub by cutting the small recess by the projection press-fitted into the small recess, said small recess having a volume smaller than that of the recess, to thereby form a recess/projection fit-engagement structure in which the projection and the recess are held in close contact with each other over an entire fit-engagement region therebetween, wherein a press-fitting margin Δd of the projection with respect to a member in which the recess is to be formed and a height h of the projection are in the following relationship: 0.3 < Δd/2h < 0.86, and wherein a corner portion devoid of roundness is provided at an edge of a press-fitting start side end surface of the projection, and a beveling of the corner portion is 0.1 mm or less. an outer member having double-row outer raceway surfaces (26, 27), an inner member (1, 24) having double-row inner raceway surfaces (28, 29), rolling elements in double rows interposed between the double-row outer raceway surfaces of the outer member and the double-row inner raceway surfaces (26, 27) of the inner member (1, 24), and an outer joint member having a shaft section, wherein the inner member (1, 24) has a hub having a hole and a flange for attachment to a wheel, and wherein the shaft section of the outer joint member is inserted into the hole of the hub and is coupled to the hub, wherein an axially extending projection provided on an outer diameter surface of the shaft section of the outer joint member is press-fitted along the axial direction into a small recess provided on an inner diameter surface of the hole of the hub, characterized in that a recess is formed in the hole of the hub by cutting the small recess by the projection press-fitted into the small recess, said small recess having a volume smaller than that of the recess, to thereby form a recess/projection fit-engagement structure in which the projection and the recess are held in close contact with each other over an entire fit-engagement region therebetween, wherein a press-fitting margin Δd of the projection with respect to a member in which the recess is to be formed and a height h of the projection are in the following relationship: 0.3 < Δd/2h < 0.86, and wherein a corner portion devoid of roundness is provided at an edge of a press-fitting start side end surface of the projection, and a beveling of the corner portion is 0.1 mm or less.