A rotation-support apparatus having construction in which large force is not applied to continuous sections between column sections 12a and rim sections 11 even when needles 6 push in the circumferential direction against the side surfaces in the circumferential direction of the column sections 12a, thus making it possible to improve the durability of a retainer 7a. Of both side surfaces in the circumferential direction of a straight section 15a on the inner-radial side in the middle section in the axial direction of the column sections 12a, the portion near the outer-radial side of the retainer 7a is more recessed than the portion near the inner-radial side of the retainer 7a. Moreover, this portion near the inner-radial side is located within the pitch circle P of the needles 6. Furthermore, there is no contact between the rolling surfaces of the needles 6 and the straight section 15a on the inner-radial side. As a result, it is possible to reduce the moment load applied to the column sections 12a from the needles 6.