The present application is applied to lamp field, and a ultrathin lamp is provided, which is configured such that a support table is provided on a mounting base and ratio of the width of the support table to the thickness of the thickest portion of the support table is set to 5.5 to 10, such that under the conditions of satisfying technological feasibility of the support base, the whole thickness of the support table and the lamp can be relatively thin, so that the overall appearance is more decorative and thus satisfying the ultrathin requirements on the market.