The present invention relates to a silver anti-tarnish agent having, as an effective component, a zinc salt and/or a zinc complex, preferably at least one kind selected from the group consisting of a carboxylic acid zinc salt having a carbon atom number of 3 to 20, a phosphoric acid zinc salt, a phosphate ester zinc salt and a carbonyl compound zinc complex; a silver anti-tarnish method for preventing tarnish of a silver part by applying said silver anti-tarnish agent to the silver part. According to the present invention, tarnish of a silver part such as a silver-plated part due to a sulfur-based gas can be prevented. The present invention is useful particularly as a silver anti-tarnish agent for a light-emitting diode and allows preventing tarnish of a silver part of a light-emitting diode and reduction in illuminance by applying the silver anti-tarnish agent of the present invention to a silver part such as a silver-plated part of a light-emitting diode for covering the silver part.