A method for producing a methanol solvate of D-tartrate of (R)-1,1,3-trimethyl-4-aminoindane, the method comprising steps (a), (b), and (c) below, and comprising adding water to a reaction system before step (c): step (a) of mixing 1,1,3-trimethyl-4-aminoindane, D-tartaric acid, and methanol to provide a mixture containing a methanol solvate of D-tartrate of (R)-1,1,3-trimethyl-4-aminoindane; step (b) of cooling the obtained mixture; and step (c) of retrieving the methanol solvate of D-tartrate of (R)-1,1,3-trimethyl-4-aminoindane.