Powder inhaler, consisting of a base housing (1), snap-in capsule receptacle (2a) mounted together with a lid (2b); a moveable mouthpiece (4) with cap (5) and guided by lateral stems (6) and vertical guide (7); a perforation device (10) for opening the capsule; a flow guide tube, centralized and housed in the mouthpiece and on the guide; a de-agglomeration chamber formed above the housing of the capsule; a vertical passage formed between said de-agglomeration chamber and the upper edge of the mouthpiece; a secondary air intake point positioned between the walls of the capsule receptacle and the base housing which in turn has one or two air intake points with a pocket and include one or more secondary air flow passages.