Provided is a method for manufacturing an interdental cleaning device (1) including a base portion (10) having a handle portion (11) and a core portion (12)； and a soft portion (20) having a cleaning soft portion (21), a non-slip portion (22), and connecting portions (23) extending from two sites of the non-slip portion (22) and being connected to the cleaning soft portion (21). The method includes causing a second gate (49) of second molds (40) and (41) for molding the soft portion (20) to open at a position substantially equally distant from positions of two communicating openings (48a) of a non-slip molding space (47) for molding the non-slip portion (22), the two communicating openings (48a) communicating with connecting portion molding spaces (48) for molding the connecting portions (23)； and charging the elastomeric material from the second gate (49) into a second molding space (42) for molding the soft portion (20) to fill the molding space (42).
