The purpose of this study was to clarify the effects of hypochlorous-acid electrolyzed water (acidic electrolyzed water, mild acidic electrolyzed water, and slightly acidic electrolyzed water), denture cleaner, and electrolyzed sodium hypochlorite water on dental alloys. Color differences, surface glosses of metal, and weight changes were measured. In addition, constituent elements were analyzed using electron probe X-ray microanalysis (EPMA). When the gold alloy and silver-palladium-gold alloy were immersed in acidic electrolyzed water, the color differences were the largest and the surface gloss decreased. When the silver alloy was immersed in slightly acidic electrolyzed water, the color difference was the largest, and the surface gloss significantly decreased in all forms of water. Pure titanium was immersed in all forms of water, but the color differences, changes in the surface gloss, and weight changes were very low. The cobalt-chromium alloy showed the largest color difference only when immersed in the electrolyzed sodium hypochlorite water, although there was no effect on the surface gloss. The EPMA image revealed the following： when the gold alloy and silver-palladium-gold alloy samples were immersed in acidic electrolyzed water, the region with high chlorine concentration and the region with high silver concentration were in good agreement. In contrast, when silver alloy immersed in denture cleaner, the region with high chlorine concentration and the region with low silver concentration were in good agreement.