The electric lamp has a lamp vessel (1) having an end portion (3) which is fixed in the lamp cap (5) by means of polyethersulphone (8) as a thermoplastic synthetic resin, which has adhered both to the lamp vessel and to the lamp cap. The end portion (3) has non-circular cross-sections where it is in contact with the synthetic resin (8) due to projections (10) projecting into the synthetic resin (8). A current supply wire (11) can be clamped between the synthetic resin (8) and the sheath portion (6) of the lamp cap (5) in order to establish electrical contact therewith. The lamp can be assembled by arranging in the hot state of the end portion (3) a polyethersulphone ring (8) around this end portion (3) and by providing the lamp cap (5) in the hot state around the polyethersulphone ring (8).