An objective is to provide an electrical-discharge surface-treatment electrode by which a high-coverage zinc coating film can be formed. The electrical-discharge surface-treatment electrode is made by uniformly distributing and compression-molding zinc-based powders including at least one of a pure-metal zinc powder and a metal zinc powder whose surface is oxidized, and zinc-oxide powders whose content rate ranges from 5 to 90 volume percent with respect to the zinc-based powders, to obtain a porosity ranging from 10 to 55 volume percent; then, the zinc coating film is formed using the electrical-discharge surface-treatment electrode.