A method for manufacturing a bearing cage molded by injecting a melted resin into a cavity from a plurality of resin injection gates provided at a peripheral portion of a substantially annular cavity formed in a mold, wherein, the bearing cage includes a substantially annular base portion (10, 10A), a plurality and an even number of pillars (20, 20A) projecting in an axial direction from an axial lateral surface (12, 12A) of the base portion (10, 10A) at a predetermined interval in a circumferential direction, and pockets (30, 30A) whose number is equal to a number of the pillars (20, 20A) formed by mutually facing surfaces (22, 22A) of a pair of adjacent pillars (20, 20A) and the axial lateral surface (12, 12A) of the base portion (10, 10A), characterized in that the resin injection gates are provided in half of a plurality of the pillars (20, 20A) respectively, the pillar (20, 20A) provided with the resin injection gate and the pillar (20, 20A) not provided with the resin injection gate are arranged alternately in the circumferential direction, a cross-sectional area of one resin injection gate is larger than cross-sectional areas of the other resin injection gates (51b, 51c, 51d) among a plurality of the resin injection gates, a resin reservoir capable of storing the melted resin is provided in: (a) the pillar (20, 20A) radially facing the pillar (20, 20A) provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates (51b, 51c, 51d) among a plurality of the pillars (20, 20A) not provided with the resin injection gate; or (b) the pillar (20, 20A) in the vicinity of the pillar (20, 20A) radially facing the pillar (20, 20A) provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates (51b, 51c, 51d) among the plurality of the pillars (20, 20A) not provided with the resin injection gate, and a cross-sectional area of a communicating portion of the resin reservoir which communicates with the pillar (20, 20A) is smaller than the smallest of cross-sectional areas of a plurality of the resin injection gates. a substantially annular base portion (10, 10A), a plurality and an even number of pillars (20, 20A) projecting in an axial direction from an axial lateral surface (12, 12A) of the base portion (10, 10A) at a predetermined interval in a circumferential direction, and pockets (30, 30A) whose number is equal to a number of the pillars (20, 20A) formed by mutually facing surfaces (22, 22A) of a pair of adjacent pillars (20, 20A) and the axial lateral surface (12, 12A) of the base portion (10, 10A), characterized in that (a) the pillar (20, 20A) radially facing the pillar (20, 20A) provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates (51b, 51c, 51d) among a plurality of the pillars (20, 20A) not provided with the resin injection gate; or (b) the pillar (20, 20A) in the vicinity of the pillar (20, 20A) radially facing the pillar (20, 20A) provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates (51b, 51c, 51d) among the plurality of the pillars (20, 20A) not provided with the resin injection gate, and