The invention relates to a treatment device designed for sequentially treating the skin in a predetermined area via a movement over this area, comprising a housing a treatment window with a width l and included in a plane a guide means adjacent to the treatment window and designed to provide information on the positioning of the device and comprising a body attached to the housing, and at least one roller having a cylindrical body of which the axis of symmetry Δ is parallel to the plane of the treatment window, the roller being mounted on the body and freely rotating relative to the body.