To provide a bearing assembly capable of axially retaining a bearing within a casing in such a way as to attain compactification in the axial direction and high economy and reliability.

Mounting of the bearing 1 can be achieved by pressing in a retaining plate 6 on a shoulder part so that the retaining plate 6 can rotate against an outer race. The bearing 1 is then supported on a shaft 4 and inserted into a compact casing 3, so that the outer case is guided to a housing 2 formed on an end wall of the casing 3. Then, the retaining plate 6 is engaged by a screw 9; therefore when it is necessary to make a fastening boss 7 concentric with a through-hole 8, the rotation thereof is possible, so that the retaining plate 6 is pressed in the axial direction against the outer race.