A treatment device, comprising:a light irradiation mechanism (54) which irradiates light of a certain wavelength region to a skin surface of an object to be treateda housing in which the light irradiation mechanism and an electric component including at least a power supply are incorporateda waterproofing sealing member which seals an accommodating portion for the electric component in said housing against the outsidefirst and second brush groups (52,53) made by making a plurality of brushes (57,58) projected on said housing into units, the brushes having translucency transmitting the light emitted by said light irradiation mechanism and being used with tip portions contacted with the skin surface of the object to be treated anda brush drive mechanism which reciprocates the first and second brush groups respectively in a direction along the skin surface in a manner that approach or separation of a tip part of the first brush group and a tip part of said second brush group tip portions of which are contacted with the skin surface of the object to be treated is repeated.
