Lifting device (10) for vertically lifting liquids, where the lifting device (10) comprises: a lifting line arrangement (18) for guiding a liquid from an open lower reservoir (16) to an upper reservoir (14); a lowering line arrangement (20) for guiding the liquid from the upper reservoir (14) to the lower reservoir (16); a pressure converter (12) with an actuating member (36), the pressure converter (12) being configured to convert a liquid pressure in the lowering line arrangement (20) into a liquid pressure in the lifting line arrangement (18) by means of a substantially linear movement of the actuating member (36); and a pump member (38) for pumping the liquid in the lifting line arrangement (18) towards the upper reservoir (14) and/or for pumping the liquid in the lowering line arrangement (20) towards the pressure converter (12).