A method of manufacturing a retainer for a roller bearing made of a metal plate and has a tubular main portion, pockets formed in the main portion intermittently concerning a circumferential direction and capable of retaining rollers rollably, and an outwardly oriented flange-like collar portion. An annular intermediate material is formed by die cutting the metal plate, and after a second intermediate material is formed by forming through holes in the intermediate material intermittently, a portion of the second intermediate material excluding a radially outer end portion is plastically deformed into a tubular shape. The portion plastically deformed tubular shape is formed as the main portion, a portion corresponding to the radially outer end portion of the second intermediate material is formed as the collar portion or a collar portion element for forming the collar portion, and portions corresponding to the through holes are formed as the pockets.