Abstract: The invention relates to a metering valve for a fluid, provided with a housing with a metering opening and a movable closing member. The closing member is biased to one of its positions by biasing means co-acting therewith in the form of a pneumatic or hydraulic spring, and can be placed in another position counter to the bias by operating means. The pneumatic or hydraulic spring can herein be driven by the fluid for metering. The closing member can be a diaphragm with a relatively stiff central portion and a relatively flexible edge portion. A supply opening connected to a feed conduit for the fluid for metering can be arranged in the housing on either side of the diaphragm. The invention further relates to a system for supplying fuel to a the combustion engine, provided with a container for the fuel and a feed line connecting the container to the engine, in which line is received one or more metering valves of the above described type.