To provide an alkynyl S,N-acetal derivative that is a new compound and to provide a method for producing the alkynyl S,N-acetal derivative by which the alkynyl S,N-acetal derivative can readily be produced and the yield can be improved.

The alkynyl S,N-acetal derivative is represented by general formula (1) (wherein, R1 denotes a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, a silyl group or an alkynyl group; R2 and R3 denote each an alkyl group or an allyl group; and R4 denotes an alkyl group). The alkynyl S,N-acetal derivative is produced as follows. A thioformamide represented by general formula (2) and an alkylating agent represented by general formula (3) (wherein, X denotes a perfluoroalkylsulfonate) are added to a solvent and an alkynylmetal reactant represented by general formula (4) (wherein, M denotes an alkali metal atom) is added.