Abstract: This reactor for the gasification of solid fuels in the powdered form, of the type employing a bath of liquid metal (5) comprises: a substantially cylindrical vessel (1) which has a substantially oblong section and lateral walls (2) and a bottom wall (3) which are lined with a refractory lining (4), this vessel further comprising an orifice (37) for discharging the bath of liquid metal, and an orifice (36) for discharging slag supernatant on the bath of liquid metal (5), a dome (11) positioned in a sealed manner on the vessel (1) and having in its upper part in the vicinity of one of the ends of the vessel a sealed box (16) for introducing an injecting branch (17) and, also in its upper part, but at the opposite end of the vessel, an orifice (21) of large section for exhausting the gases produced, and a roughly central orifice (29) for introducing addition elements; and means (8, 9, 10a-e, 6, 13, 14, 15) for cooling the lateral walls and the bottom wall of the vessel and the dome.