A dispenser is provided for the delivery of controlled, metered amounts of any of numerous different substances to humans or animals, such as medicaments, pharmaceuticals, cosmetics, and food products, or to deliver materials that may react upon exposure to air, such as glue. Means are provided in the dispenser to effect controlled delivery of a pre-determined amount of the substance contained in the dispenser. A one-way valve is provided to hermetically seal the portion of the dispenser containing the substance to be dispensed.
