To effectively remove cations and anions from a mercaptoazole compound produced by conventional method and to purify the compound to enable the use as an agent for electronic industry by dissolving a specific mercaptoazole compound in an organic solvent, adding water to the solution and recovering the crystallized product.

The objective compound can be purified by dissolving (A) a mercaptoazole compound of formula (Z is an atomic group forming a heterocyclic group together with N) (e.g. 1-phenyl-5-mercaptotetrazole) in (B) an organic solvent, preferably an alcohol such as methanol and ethanol preferably at 40-60°C, adding (C) pure water having an electrical conductivity of preferably ≤10 μS/cm to the solution, crystallizing preferably at 15-50°C, separating into solid and liquid preferably at 15-50°C and recovering the objective compound. The amounts of the components B and C are 2-5 pts.wt. and 8-12 pts.wt. based on 1 pt.wt. of the component A, respectively.