The invention relates to a method and a device (1) for producing a multi-wall vitreous body (20) provided with a vitreous membrane (25) for a chemical sensor or a measuring probe provided with at least one wall or internal tube which are arranged therein and partially meltable, thereby possibly closing a first chamber (291). According to said invention, a vitreous element (286) for absorbing radiation energy is introduced in the area of the section (210) of the meltable wall or the internal tube (21). Afterwards, said vitreous element is exposed to a radiation energy effect in such a way thatsaid vitreous element (286) and the section (210) of the wall or the internal tube (21) are fused with the aid of at lest one energy radiator (17).