An apparatus for cleaning the oral cavity comprises: a body including insertion slots into which the teeth of a user can be inserted, a plurality of injection holes and a plurality of aspiration holes formed on the inner wall of the insertion slots a feeding tube for supplying cleaning liquid to the plurality of injection holes a discharge tube through which the cleaning liquid is externally discharged via the plurality of aspiration holes and a switching member for switching the direction of injection and the direction of aspiration of the cleaning liquid, wherein the body includes a first inner space which communicates with the plurality of injection holes, and a second inner space which communicates with the plurality of aspiration holes.
