An iron unit adapted to be used with a hair dryer includes an ironing plate formed of a heat conductor having a groove and an exhaust groove in communication with the groove on a lower side thereof providing a contact surface with an object to be heated, and a plurality of air outlets extending from the upper side to the groove. A hot air source receiver includes a mounting plate having a cylindrical member engageable with the hair dryer for supplying hot air. A hot air-feeding space is in communication within the cylindrical member. The mounting plate is attached to the ironing plate, with the hot air-feeding space being in communication with the outside through a plurality of passages. A covering member defines a space on the outside of the engaging cylindrical member of the hot air source receiver. The mounting plate is attached in place with the space being in communication with the outside on the side of the cylindrical member and on the peripheral side of the mounting plate. The iron unit may further include a holder for holding the iron plate.