To provide method for manufacturing interdental cleaner for suppressing elastomer from insufficiently filling into space around shaft portion in filling the elastomer into mold. Method for manufacturing interdental cleaner includes first step of molding base portion having handle portion and shaft portion (40) by filling composite material into first mold, and second step of forming cleaning portion, slip resistance portion and coupling portion by filling elastomer into second mold (200) from distal end portion side of shaft portion (40) with base portion situated in second mold (200), second mold (200) having second space for forming cleaning portion, slip resistance portion and coupling portion. What is used as second mold (200) in second step has ratio no less than 40% of a flow path area in second space for elastomer around distal end portion of handle portion to flow path area in second space for elastomer around proximal end portion of shaft portion (40).