1-Benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine or hydrochloride thereof, which is useful as a drug, can be produced in high purity by safer and easier operations suitable for industrial production by subjecting 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidene]methyl-piperidine or a solvate thereof to catalytic hydrogenation in the presence of a palladium-alumina catalyst and if necessary, converting the thus obtained compound to its hydrochloride.