A wash brush having a handle securely coupleable with a cleaning head by a ratchet-like coupling mechanism, and including a flowpath control mechanism operable to direct and control a stream of liquid to the brush head area. The controller makes the setting so that the target power of the engine monotonically increases with the decrease in the remaining electric amount of the electrical storage device. A power supply drives the LED light sources according to a driving signal having a magnitude between a minimum driving signal and a maximum driving signal, wherein the LED light sources sequentially illuminate in response to the magnitude of the driving signal.