An electric toothbrush that detects plaque on the teeth, ensures accurate plaque detection, and performs cleaning of plaque. The electric toothbrush may include a drive module having a first drive for oscillating a brush unit in a first direction and a second drive for oscillating the brush unit in a second direction; a light emitting module; a reflected light detector; a plaque detector for detecting plaque based on reflected light detected by the reflected light detector; a liquid spray part for spraying liquid from the brush unit; and a liquid spray controller for controlling a spray timing of the liquid. The liquid spray controller may spray the liquid when the amount of plaque detected by the plaque detector exceeds a threshold. The drive module may stop the first drive and perform only the second drive while the liquid is being sprayed.