A method for manufacturing a bearing device which includes a rolling bearing having a plurality of rolling elements arranged between an inner ring and an outer ring, and a retainer plate configured to retain the rolling bearing to a housing and having a circular hole to be fitted to an outer peripheral surface of the outer ring of the rolling bearing, wherein an outer periphery of an axial end portion of the outer ring is provided with a small-diameter step portion to be fitted with the retainer plate, an engagement groove extending in a circumferential direction is formed in an outer peripheral surface of the small-diameter step portion, a groove depth of the engagement groove with respect to the outer peripheral surface of the small-diameter step portion is constant over the entire circumference, and the circular hole of the retainer plate is provided with a plurality of engagement parts protruding radially inward to be engaged to the engagement groove, the method comprising: a formation process including arranging the circular hole of the retainer plate around the small-diameter step portion of the outer ring, pushing the retainer plate in a radial direction towards the small-diameter step portion of the outer ring at a circumferential position where one of the plurality of engagement parts is to be formed, and characterized in that, the plurality of engagement parts are formed sequentially, the retainer plate is pushed towards the small-diameter step portion of the outer ring in a state, in which a center of the retainer plate and a center of the outer ring are eccentric with each other, when the retainer plate is pushed towards the small-diameter step portion of the outer ring a gap along a radial direction between an inner peripheral surface of the retainer plate and an outer peripheral surface of the small-diameter step portion at the position where the one of the plurality of engagement parts is to be formed disappears, and at a time when the retainer plate is pushed towards the outer ring in a radial direction, a peripheral edge portion of the circular hole of the retainer plate is pressed with a punch in an axial direction to form the one of the engagement parts, such that a tip of the engagement part is in contact with the engagement groove a formation process including arranging the circular hole of the retainer plate around the small-diameter step portion of the outer ring, pushing the retainer plate in a radial direction towards the small-diameter step portion of the outer ring at a circumferential position where one of the plurality of engagement parts is to be formed, and the plurality of engagement parts are formed sequentially, the retainer plate is pushed towards the small-diameter step portion of the outer ring in a state, in which a center of the retainer plate and a center of the outer ring are eccentric with each other, when the retainer plate is pushed towards the small-diameter step portion of the outer ring a gap along a radial direction between an inner peripheral surface of the retainer plate and an outer peripheral surface of the small-diameter step portion at the position where the one of the plurality of engagement parts is to be formed disappears, and at a time when the retainer plate is pushed towards the outer ring in a radial direction, a peripheral edge portion of the circular hole of the retainer plate is pressed with a punch in an axial direction to form the one of the engagement parts, such that a tip of the engagement part is in contact with the engagement groove