The present invention relates to a dry cleaning device and method using atmospheric pressure plasma and steam. The device according to the present invention comprises: a chuck in which a silicon substrate having a silicon oxide and a silicon nitride formed therein is arranged; an RF electrode to which RF power for generating plasma is applied; a shower head spaced apart from the RF electrode with a plasma generation area therebetween; and a steam supply device for supplying high-temperature cleaning gas to the shower head, wherein reaction gas supplied to the plasma generation area is plasma-treated with the RF power so as to be supplied to the silicon substrate, and thus the silicon oxide and the silicon nitride are changed to a reaction layer including ammonium hexafluorosilicate ((NH4)2SiF6), and the high-temperature cleaning gas supplied by the steam supply device is sprayed onto the reaction layer through the shower head so as to remove the reaction layer. According to the present invention, the time required for removing a reaction layer during a dry cleaning process is shortened, and overall processing time can be reduced.