To provide a pressure regulating valve with a piston capable of obtaining stable damper effects at all times, the pressure regulating valve wherein an excessive lift is prevented by suppressing excessive reaction of the piston, durability is improved, and stable pressure regulation can be performed.

A pressure regulating valve includes: a valve body in which a control fluid can flow into an internal space; a discharge port for discharging the control fluid flowing into the valve body; a piston capable of sliding inside of the valve body; and a spring for biasing the piston toward the one end side of the valve body. The pressure regulating valve regulates pressure inside a flow path where the control fluid flows, to a predetermined pressure by discharging the control fluid flowing into the valve body from the discharge port. In the pressure regulating valve, a columnar space with a bottom is provided, which is opened in a direction opposite to a direction where the spring is located, in the piston. At the one end side of the valve body, a rod member which is inserted into the columnar to form a damper chamber together with the piston is provided.