A roller bearing retainer (13) includes a pair of annular ring parts (14) and a plurality of column parts (15) each including a column center part (16) provided in an axial center region so as to be positioned relatively on the radial inner side, a pair of column end parts (17) provided in axial end regions so as to be positioned relatively on the radial outer side, and a pair of column sloped parts (18) positioned between the column center part (16) and the pair of column end parts (17), and connecting the pair of ring parts to each other. A thickness of each part of the column center part, the pair of column end parts, and the pair of column sloped parts is smaller than a thickness of a boundary part between the adjacent parts.