A roller bearing cage for rotatably holding, at a predetermined interval, rollers (15A; 15B) serving as rolling elements of a roller bearing, the roller bearing cage being provided with a plurality of pocket holes (P) at equal intervals in a circumferential direction for housing the rollers (15A; 15B), wherein a plurality of columns connect a pair of rings that are apart from each other in an axial direction, each of the columns , which is positioned between the pocket holes (P) adjacent to each other, includes: a center guide portion for guiding the rollers (15A; 15B), the center guide portion being positioned at an axially center of the column in a radially outside of a pitch circle diameter of the rollers (15A; 15B); and a pair of end portions each of which is connected to the center guide portion at one end and to a corresponding one of the rings at the other end in the radially outside of the center guide portion , each of the end portions of the column has a retaining projection so that the retaining projection is positioned, in each of the pocket holes (P), diagonally opposite to another retaining projection , characterized in that : an axial-direction relief portion is provided, in each of the pocket holes (P), diagonally opposite to another axial-direction relief portion in a corner of the pocket hole (P) where the retaining projection is provided, and a circumferential-direction relief portion is provided, in each of the pocket holes (P), diagonally opposite to another circumferential-direction relief portion in a corner of the pocket hole (P) where no retaining projection is provided. a plurality of columns connect a pair of rings that are apart from each other in an axial direction, each of the columns , which is positioned between the pocket holes (P) adjacent to each other, includes: a center guide portion for guiding the rollers (15A; 15B), the center guide portion being positioned at an axially center of the column in a radially outside of a pitch circle diameter of the rollers (15A; 15B); and a pair of end portions each of which is connected to the center guide portion at one end and to a corresponding one of the rings at the other end in the radially outside of the center guide portion , a center guide portion for guiding the rollers (15A; 15B), the center guide portion being positioned at an axially center of the column in a radially outside of a pitch circle diameter of the rollers (15A; 15B); and a pair of end portions each of which is connected to the center guide portion at one end and to a corresponding one of the rings at the other end in the radially outside of the center guide portion , each of the end portions of the column has a retaining projection so that the retaining projection is positioned, in each of the pocket holes (P), diagonally opposite to another retaining projection , characterized in that : an axial-direction relief portion is provided, in each of the pocket holes (P), diagonally opposite to another axial-direction relief portion in a corner of the pocket hole (P) where the retaining projection is provided, and a circumferential-direction relief portion is provided, in each of the pocket holes (P), diagonally opposite to another circumferential-direction relief portion in a corner of the pocket hole (P) where no retaining projection is provided. an axial-direction relief portion is provided, in each of the pocket holes (P), diagonally opposite to another axial-direction relief portion in a corner of the pocket hole (P) where the retaining projection is provided, and a circumferential-direction relief portion is provided, in each of the pocket holes (P), diagonally opposite to another circumferential-direction relief portion in a corner of the pocket hole (P) where no retaining projection is provided. <EOS>