A unit dose dry powder inhaler includes a chamber housing containing a powder dispersion chamber. A chamber tube extends from the dispersion chamber into the mouthpiece. A cover or cup is rotatably attached to the chamber housing. A dose of a dry powder is contained at a powder location in the chamber housing. An air passageway leading from the powder location to the dispersion chamber is closed off by the cover. When the cover is rotated to an open position, the air passageway is opened. The user inhales on the mouthpiece drawing air through the powder location, the air passageway, the dispersion chamber and the chamber tube, through the mouthpiece and into the users lungs. The unit dose of dry powder is stored directly in, or is part of, the inhaler.