To provide a manufacturing method of an interdental cleaning implement capable of effectively preventing molding defects of a cleaning soft portion by preventing deformation of a core part, when molding the cleaning soft portion using an elastomer material.SOLUTION: The manufacturing method includes a soft portion molding step: of setting at least a part of a core base material 12 out of a plurality of base materials 10, on a plurality of second molding spaces 42 of a second metallic molds 40 and 41； and, at least two sets of holding pins, two holding pins in facing arrangement defined as one set, facingly arranged so as to project into respective cleaning soft portion molded portions 46 in the substantially orthogonal direction to mating surfaces 40a and 40b of second metallic molds 40 and 41, supplies an elastomer material to the plurality of cleaning soft portion molded portions 46, with the at least two portions in the lengthwise direction of the core material held with the at least two sets of holding pins, where at least one set of two holding pins in facing arrangement are displaced in the longitudinal direction of the cleaning soft portion molded portions, and molding a soft portion 20.SELECTED DRAWING: Figure 11【課題】エラストマ材料を用いて清掃用軟質部を成形するときにおける、芯部の変形を防止して、清掃用軟質部の成形不良の発生を効果的に防止し得る歯間清掃具の製造方法を提供する。【解決手段】複数個の基材部１０のうちの少なくとも芯基材部１２の一部を、第２金型４０、４１の複数個の第２成形空間４２にセットし、第２金型４０、４１の合わせ面４０ａ、４０ｂと略直交状に各清掃用軟質部成形部４６内に突出するように対向配置した２本の保持ピンを１組とする少なくとも２組の保持ピンであって、少なくとも１組の対向配置した２本の保持ピンを清掃用軟質部成形部の長手方向にずらして配置した少なくとも２組の保持ピンで、芯本体の長さ方向の少なくとも２か所を保持した状態で、複数の清掃用軟質部成形部４６に対してエラストマ材料を供給して軟質部２０を成形する軟質部成形工程を備えた。【選択図】図１１
