TOOTHBRUSH

This toothbrush is provided with a main body that includes: a head part (4) having a raised bristle surface (4a) on which bristles (210) are erected; a grip part; and a neck part. The inside of the main body is provided with: a light-emitting part (50) that emits light (L) toward a tooth surface (99a) through a specific region (4c) of the raised bristle surface (4a); and a light-receiving part (51) that receives a radiant light (L') caused by said light from the tooth surface through the specific region (4c). The presence or absence of plaque on the tooth surface (99a) is determined on the basis of an output of the light-receiving part (51). A light receiving and condensing part (53), which condenses the radiant light (L') from the tooth surface (99a) toward a light-receiving surface of the light-receiving part (51), is disposed in a housing portion that forms the specific region (4c). A region that includes the specific region (4c) in the raised bristle surface (4a) of the head part (4) and is wider than the