The object of the invention is to increase the efficiency of a low-pressure steam turbine connected to a condenser and to reduce its cost of manufacture. According to the invention this is achieved when the dividing plane (8) of the top and bottom part (6, 7) of the outer casing (1) of the low-pressure steam turbine lies at the level of the axis (9) of the turbine rotor (4) and the concrete foundation (14) reaches up to the dividing plane (8). Both the bottom part (7) of the outer casing (1) and the bearing points (10) of the turbine rotor (4) are secured in the concrete foundation (14). The outer casing (1) is designed to be open at least on one side at right angles to and horizontally to the axis (9) of the turbine rotor (4). A condenser (16) is attached to each lateral opening (17) in the outer casing (1). The top part (6) of the outer casing (1) consists of an assembly hood (19) and, for each condenser (16), a frame part (20) connected to the latter and the bottom part (7) by retention of self substance or in a non-positive manner. The assembly hood (19) is connected to both the bottom part (7) of the outer casing (1) and each frame part (20) in a non-positive or positive-locking manner, one frame part (20) each being arranged between a condenser (16) and the assembly hood (19).