The present invention achieves construction of a multipoint contact ball bearing that is able to prevent the rolling surfaces of the balls 4 from becoming damaged and can keep the durability of the bearing from decreasing while maintaining the radial load capacity even when large radial loads act and the rolling surfaces of the balls 4 coming in contact with the inner raceway bottom section 8a. The inner raceway 5a is complex curved surface that comprises a pair of inner raceway side surface sections having a generating line shape with a radius of curvature that is larger than 50% the diameter of the balls 4, and an inner raceway bottom section 8a that connects the edges of the inside end in the width direction of the pair of inner raceway side surface sections 7a; with the inner raceway bottom section 8a big a concave curved surface having a generating line shape with a radius of curvature R 8 that is less than 50% the diameter of the balls 4. The edges of both sides in the width direction of the inner race
