A laundry treating apparatus comprising: a dryer including: a first cabinet comprising: a first laundry loading opening; and a first door for opening and closing the first laundry loading opening; and a first drum for receiving laundry, the first drum being rotatably disposed in the first cabinet; a washing machine including: a second cabinet comprising: a second laundry loading opening; and a second door for opening and closing the second laundry loading opening; a tub disposed in the second cabinet; and a second drum for receiving laundry, the second drum being rotatably disposed in the tub; wherein the laundry treating apparatus comprises: a refresher including a third cabinet disposed at a lateral side of the dryer and the washing machine, the third cabinet comprising: an inner space for receiving laundry; an opening; and a third door for opening and closing the opening; a duct system including: a first supply air duct configured to supply air into the first drum; a second supply air duct configured to supply air into the inner space of the third cabinet; and a heat exchange channel connected to the first supply air duct and the second supply air duct; and a heating device configured to heat air passing through the heat exchange channel, characterized in that the heating device includes: a base plate; a first wall extending upwardly from the base plate; a second wall extending upwardly from the base plate and spaced apart from the first wall; and a cover disposed above the first wall and the second wall, and wherein the heat exchange channel is a space surrounded by the base plate, the first wall, the second wall, and the cover. a dryer including: a first cabinet comprising: a first laundry loading opening; and a first door for opening and closing the first laundry loading opening; and a first drum for receiving laundry, the first drum being rotatably disposed in the first cabinet; a first cabinet comprising: a first laundry loading opening; and a first door for opening and closing the first laundry loading opening; and a first laundry loading opening; and a first door for opening and closing the first laundry loading opening; and a first drum for receiving laundry, the first drum being rotatably disposed in the first cabinet; a washing machine including: a second cabinet comprising: a second laundry loading opening; and a second door for opening and closing the second laundry loading opening; a tub disposed in the second cabinet; and a second drum for receiving laundry, the second drum being rotatably disposed in the tub; wherein the laundry treating apparatus comprises: a second cabinet comprising: a second laundry loading opening; and a second door for opening and closing the second laundry loading opening; a second laundry loading opening; and a second door for opening and closing the second laundry loading opening; a tub disposed in the second cabinet; and a second drum for receiving laundry, the second drum being rotatably disposed in the tub; wherein the laundry treating apparatus comprises: a refresher including a third cabinet disposed at a lateral side of the dryer and the washing machine, the third cabinet comprising: an inner space for receiving laundry; an opening; and a third door for opening and closing the opening; an inner space for receiving laundry; an opening; and a third door for opening and closing the opening; a duct system including: a first supply air duct configured to supply air into the first drum; a second supply air duct configured to supply air into the inner space of the third cabinet; and a heat exchange channel connected to the first supply air duct and the second supply air duct; and a first supply air duct configured to supply air into the first drum; a second supply air duct configured to supply air into the inner space of the third cabinet; and a heat exchange channel connected to the first supply air duct and the second supply air duct; and a heating device configured to heat air passing through the heat exchange channel, characterized in that the heating device includes: a base plate; a first wall extending upwardly from the base plate; a second wall extending upwardly from the base plate and spaced apart from the first wall; and a cover disposed above the first wall and the second wall, and a base plate; a first wall extending upwardly from the base plate; a second wall extending upwardly from the base plate and spaced apart from the first wall; and a cover disposed above the first wall and the second wall, and wherein the heat exchange channel is a space surrounded by the base plate, the first wall, the second wall, and the cover.