To provide a simple method for producing a 5-amino-4-nitrosopyrazole derivative from an easily available raw material in a high yield.

This method for producing the 5-amino-4-nitrosopyrazole derivative represented by general formula (2) (R is H, or an alkyl or an aryl which may have one or more substituents) is characterized by subjecting a 3- hydrazono-2-hydroximinopropionitrile derivative represented by general formula (1) to a cyclization reaction.