A powder inhaler for medication, for example for treatment of asthma. The inhaler has a rotatable and/or displaceable active substance magazine which has several apertures for medication. The magazine is moved with the aid of a control curve mechanism by rotation and/or displacement in such a manner that a chamber prefilled with active substance mixture is always located in front of the air inlet opening. The respiratory air stream of the patient is guided through the apparatus in such a manner that the air stream empties the chamber with the active substance mixture. The active substance mixture is divided up into respirable particles in a cyclone chamber or against an impact plate and then surrounded with a jacket stream of pure air and inhaled.