To provide a treating device and a treating method of sewing cloth, comprising simple mechanisms, corresponding to various cloths and having versatility.

The device includes a supplying unit 1 supplying a cloth 8, a relax unit 2 ejecting steam to the cloth 8 from the transfer belt 7 side, a wet heat press unit 3 pressing the cloth 8 from the upper side, and simultaneously ejecting steam from a press 19 and sucking from the transfer belt 7 side, an aging unit 4 further ejecting steam to the cloth 8 from the upper side and the transfer belt 7 side, a drying unit 5 blowing hot air to the cloth 8 from the upper side and sucking to the transfer belt 7 side, and a cooling unit 6 cooling the cloth 8 to be the room temperature, wherein each unit is connected to be recombinable, transfer belt 7 includes one sheet, and the identical plane is formed on the transfer belt 7 from the relax unit 2 to the cooling unit 6.