Abstract: There is provided an inhaler device comprising a housing, a mouthpiece, a seat for receiving a unit dose blister and a punch for piercing a lid of the unit dose blister. The housing comprises a base and a lid pivotally joined by a hinge, such that the lid is pivotable from a first ‘closed’ position in which it abuts the base to define a cavity, to a second ‘open’ position in which the cavity can be accessed. The seat and the punch are adapted to lie within the cavity when the lid is in the first ‘closed’ position and moving the lid from the ‘open’ position to the ‘closed’ position causes the punch to pierce a lid of a unit dose blister received in the seat. Only the lid of the unit dose blister is pierced.