Plasmonic chemical reactions triggered by the excitation of a localized surface plasmon show unique reactivity in a highly localized electric field. In this study, visible light driven hydrogen evolution reactions have been successfully induced by the combination of plasmonic Ag nanostructures with a p-type GaP semiconductor electrode. Through photoelectrochemical measurements, the unique reactivity of the plasmon-induced electron transfer reaction, especially under neutral conditions, has been confirmed.