The invention relates to a disposable breath-actuated inhaler comprising a tubular housing forming an air flow path being open at both ends, one end forming an air inlet (4) and one end forming an air outlet (5), the housing comprising a compartment (3) for storing a pharmaceutical powder to be inhaled. The compartment (3) for storing the pharmaceutical powder is located close to the air inlet (4) and is covered by a thin foil (6) sealing the compartment in an airtight way which can be removed from the compartment from outside the housing, the housing being shaped with a constriction (9) adjacent the powder compartment (3) such that a turbulent air stream will be obtained at the constriction upon inhalation which will lift the powder out from the compartment (3) and mix the powder into the air stream.