A manufacturing method of a roller bearing cage having a diameter of 1 to 3 m, the cage being configured such that a pair of ring parts (4, 6) axially separated is connected by a plurality of column parts sliding on an outer peripheral surface of a roller as a rolling element, and a plurality of pocket holes is evenly formed in a circumferential direction to store and hold the roller at a peripheral wall portion, wherein the manufacturing method comprises: a base body blank cutting step of cutting a steel plate having a thickness of 8 to 16 mm so as to protrude portions to be the column parts outward in a radial direction from an outer peripheral portion of a disc-shaped member with a central hole and form engagement convexes at leading ends of the portions to be the column parts, thereby to obtain a base body blank; a folding step of folding the portions to be the column parts in the base body blank along the outer peripheral portion of the disc-shaped member; a connection body blank cutting step of cutting a steel plate having a thickness of 8 to 16 mm so as to form engagement concaves evenly in the circumferential direction in an annular ring part for engagement with the engagement convexes, thereby to obtain a connection body blank; a joining and fixing step of joining and fixing the base body and the connection body while the engagement convexes of the base body formed from the base body blank are engaged with the engagement concaves of the connection body formed from the connection body blank; a surface pressing step of surface-pressing the portions to be the column parts to form and finish contact surfaces with respect to the roller as predetermined inclined surfaces, the surface pressing step being performed after the base body blank cutting step or the folding step; and an inner-diameter removing step of removing an excessive thick portion of an inner-diameter portion of the disc-shaped member to meet a desired inner diameter, the inner-diameter removing step being performed after the folding step in the case where the surface pressing step is performed after the base body blank cutting step, or being performed after the surface pressing step in the case where the surface pressing step is performed after the folding step, or being performed after the joining and fixing step. a base body blank cutting step of cutting a steel plate having a thickness of 8 to 16 mm so as to protrude portions to be the column parts outward in a radial direction from an outer peripheral portion of a disc-shaped member with a central hole and form engagement convexes at leading ends of the portions to be the column parts, thereby to obtain a base body blank; a folding step of folding the portions to be the column parts in the base body blank along the outer peripheral portion of the disc-shaped member; a connection body blank cutting step of cutting a steel plate having a thickness of 8 to 16 mm so as to form engagement concaves evenly in the circumferential direction in an annular ring part for engagement with the engagement convexes, thereby to obtain a connection body blank; a joining and fixing step of joining and fixing the base body and the connection body while the engagement convexes of the base body formed from the base body blank are engaged with the engagement concaves of the connection body formed from the connection body blank; a surface pressing step of surface-pressing the portions to be the column parts to form and finish contact surfaces with respect to the roller as predetermined inclined surfaces, the surface pressing step being performed after the base body blank cutting step or the folding step; and an inner-diameter removing step of removing an excessive thick portion of an inner-diameter portion of the disc-shaped member to meet a desired inner diameter, the inner-diameter removing step being performed after the folding step in the case where the surface pressing step is performed after the base body blank cutting step, or being performed after the surface pressing step in the case where the surface pressing step is performed after the folding step, or being performed after the joining and fixing step.