An inhaler has a tubular case defining inside a flow route for medicament. A capsule containing the medicament serving as its source is on the upstream side and a mouthpiece is on the opposite downstream side. A rotor with a convex surface on the upstream side is rotatably placed in the flow route inside the tubular case. A motor rotates the rotor when a patient breathes in the medicament such that a shearing force will operate on the medicament particles and the medicament is separated from lactose.
