Abstract: A pressure regulating valve (20) for adjusting a pressure of a supply/discharge passage (10) to a pressure balanced against a weight of a body to be carried (1) is provided. The supply/discharge passage (10) is connected to a working chamber (8) of a cylinder (2) for raising and lowering the body to be carried (1). A control valve (38) for increasing and decreasing a pressure in a control passage (28) in accordance with a balance between the weight of the body to be carried (1) and a working force in a reaction force chamber (42) to which a pilot pressure is introduced from the control passage (28) is also provided.