Abstract: An oral care device for providing oral-cavity information to a user or a manager includes: a liquid supply unit; a mouthpiece connected to the liquid supply unit and including a spatial portion configured to accommodate at least one of an upper tooth side and a lower tooth side when the mouthpiece is inserted into an oral cavity; a pump connected to the mouthpiece and configured to suction liquid from the liquid supply unit and introduce the liquid into the spatial portion and to suction fluid from the spatial portion; a storage unit connected to the pump and configured to store or discharge fluid suctioned from the spatial portion; and a measuring unit connected to the storage unit and configured to measure a state of fluid stored in the storage unit, wherein liquid is introduced to the spatial portion from the liquid supply unit only by suction force of the pump.