A method for manufacturing a one-way clutch cage allows slits of the cage to be formed with a short punching distance, wherein the slits are narrow in width and the cage is less prone to deformation. In this method for manufacturing a one-way clutch cage, after slits 8, 10, 11, 12 have been formed, windows 17 are formed and then an outer annular part 18 is cut. Therefore, since the slits can be formed in a cylindrical member 2 that has not yet been subjected to the window formation process of the outer annular part cut-out process, and that is sufficiently strong, a radially diagonal punching operation can be performed to form the slits. During this radially diagonal punching operation, a boundary portion between a cylindrical portion 3 and an outer flange 5 is punched out from an inside of the cylindrical member toward an outside of the cylindrical member. Thus, the punching distance can be shortened, the punching die can be thinned in thickness and the slit width can be reduced, as compared with horizontal punching.