A furnace for vacuum-pressure-sintering has a furnace chamber which is enclosed in and insulated from a surrounding pressure chamber. The pressure chamber includes a bottom projecting into it at the lower end and has at the upper end a charging opening and a lid projecting into the charging opening. A housing can be applied over the charging opening and connected to a vacuum pump during the part of the operating cycle when the pressure in the furnace is to be below atmospheric pressure. The lid is formed of an outer annular part and an inner part, separate from each other, the outer annular part remaining in position when the inner part is removed. A heat radiation protection ring is provided for insertion into the opening into the annular part when the annular part is raised. A lifting device for the lid is provided inside the housing.