Abstract: Manufacturing tubeless executed high pressure ceramic or monocrystalline vacuum metal vapor lamps. The substance introduced into the discharge tube is degassed by heating the tube at least once before sealing it finally. The equipment employed in carrying out the method preferably comprises two heaters to be accommodated at the ends of the discharge tube, the heat zone of which is about 1/3 of the discharge tube length. The additives are placed into the sealed end of the discharge tube, and while heated, the tube is pumped on the other end. The additives precipitate on the colder wall parts of the discharge tube, but at the same time it is also freed from its gas content. Thereafter the precipitate is evaporated by heat treatment. This double evaporation results in a high grade degassing of the substance. Afterwards the opposite end of the discharge tube is finally sealed.