A metering valve for dispensing an accurately metered dose of a product includes a valve stem having at one end a piston extending within and slidable relative to a cup shaped valve body. A spring member urges the piston against a base of the valve body. Movement of the valve stem against the spring action causes the piston to move away from the base of the valve body to define a temporary metering chamber between the valve stem and valve body. A clearance between an outer surface of the piston and an inner surface of the valve body provides a path for the product to flow from the container to the metering chamber. A seal within the container is contacted by an end of the piston to prevent the flow of product along the path, and the product is dispensed from the temporary metering chamber through an outlet in the valve stem.