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 &lsquoclosed&rsquo position in which it abuts the base to define a cavity, to a second &lsquoopen&rsquo 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 &lsquoclosed&rsquo position and moving the lid from the &lsquoopen&rsquo position to the &lsquoclosed&rsquo 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.
