The present invention provides a method for producing an indazol-3-ylmethyl phosphonium salt represented by Formula (IV): [wherein X represents halogen, OSO2Ra (wherein Ra represents substituted or unsubstituted lower alkyl, substituted or unsubstituted aryl or the like), or OC(═O)Rb (wherein Rb has the same meaning as the above Ra), or the like, and R1, R2 and R3 may be the same or different and each represents substituted or unsubstituted aryl or the like] or a salt thereof, which comprises reacting a compound represented by Formula (I): a compound represented by Formula (II): H—X  (II) (wherein X has the same meaning as defined above), and a compound represented by Formula (III): (wherein R1, R2 and R3 have the same meanings as defined above, respectively), and the like.