A lifting device for an industrial truck comprising - a lifting frame comprising a movably guided load part and at least one movably guided mast stage, - a free lift cylinder acting on the load part, - at least one mast lift cylinder acting on the at least one mast stage, - a hydraulic unit (16, 28) for supplying the free lift cylinder and the at least one mast lift cylinder with hydraulic fluid, - at least one supply valve (100, 110, 120, 130) which is connected to the hydraulic unit (16, 28) and to the free lift cylinder or to the at least one mast lift cylinder and which is provided only for supplying hydraulic fluid from the hydraulic tank to the free lift cylinder or to the mast lift cylinder and - at least one return valve (30, 30', 30") which is connected to the hydraulic unit (16, 28) and to the free lift cylinder and/or to the at least one mast lift cylinder and which is provided only for returning hydraulic fluid from the free lift cylinder and/or the mast lift cylinder to the hydraulic tank, characterized in that - a supply line is divided upstream of the hydraulic unit (16, 28) into a first connecting line which is connected to the free lift cylinder and into a second connecting line which is connected to the mast lift cylinder, wherein the supply valve (100, 110, 120, 130) is arranged as a proportional valve in the first connecting line and a pressure (pi) required for actuating the free lift cylinder is lower than a pressure required for actuating the mast lift cylinder or wherein the supply valve (100, 110, 120, 130) is arranged as a proportional valve in the second connecting line and a pressure (pi) required for actuating the free lift cylinder is higher than a pressure required for actuating the mast lift cylinder. - wherein the supply valve (100, 110, 120, 130) has a blocked position (100a, 120a, 130a) and a throughflow position (100b, 120b, 130b). - a lifting frame comprising a movably guided load part and at least one movably guided mast stage, - a free lift cylinder acting on the load part, - at least one mast lift cylinder acting on the at least one mast stage, - a hydraulic unit (16, 28) for supplying the free lift cylinder and the at least one mast lift cylinder with hydraulic fluid, - at least one supply valve (100, 110, 120, 130) which is connected to the hydraulic unit (16, 28) and to the free lift cylinder or to the at least one mast lift cylinder and which is provided only for supplying hydraulic fluid from the hydraulic tank to the free lift cylinder or to the mast lift cylinder and - at least one return valve (30, 30', 30") which is connected to the hydraulic unit (16, 28) and to the free lift cylinder and/or to the at least one mast lift cylinder and which is provided only for returning hydraulic fluid from the free lift cylinder and/or the mast lift cylinder to the hydraulic tank, characterized in that - a supply line is divided upstream of the hydraulic unit (16, 28) into a first connecting line which is connected to the free lift cylinder and into a second connecting line which is connected to the mast lift cylinder, wherein the supply valve (100, 110, 120, 130) is arranged as a proportional valve in the first connecting line and a pressure (pi) required for actuating the free lift cylinder is lower than a pressure required for actuating the mast lift cylinder or wherein the supply valve (100, 110, 120, 130) is arranged as a proportional valve in the second connecting line and a pressure (pi) required for actuating the free lift cylinder is higher than a pressure required for actuating the mast lift cylinder. - wherein the supply valve (100, 110, 120, 130) has a blocked position (100a, 120a, 130a) and a throughflow position (100b, 120b, 130b).