A controller apparatus for a faucet, for controlling the faucet using energy created by electric power generation, wherein all components used therein keep necessary performance thereof for a long period of time and wherein no components require exchange thereof until the product service-life of the faucet apparatus is reached, thereby realizing true maintenance-free apparatus. The controller apparatus for a faucet comprises a capacitor; a voltage conversion means for converting the capacitor voltage to a predetermined voltage; a faucet controller circuit operated with electricity supplied from the voltage conversion means; and an electromagnetic valve for opening or closing a flow passage by said faucet controller circuit. The controller apparatus for a faucet further comprises an electric power generation means and a primary battery, and the capacitor is charged with either of an output of the electric power generation means and the primary battery.