A method and a device for ironing items of clothing with sleeves, especially, shirts and blouses, by a form finisher include an inflatable bag placed inside the item of clothing when it is being ironed. The inflatable bag extends to the sleeves of the item of clothing. For the sleeves to be ironed in a smoother manner, the ends of the inflatable bag can be provided with a reinforcement that extends to the sleeves. Also, to enable the vents, which are situated above the sleeves, to keep their shape (the overlap und underlap), the inflatable bag can also be supplied, therefore, with reinforcement. An inner tensioning mechanism that is inserted inside the area of the sleeve can improve the smoothness even further.