A substrate processing apparatus and a method of fabricating the same are proposed. A bonding layer, by which a chuck body and a base plate of an electrostatic chuck device are bonded, is completely covered using a double-sealing structure in which a covering member for preventing a processing gas from infiltrating into the bonding layer and a sealing member for preventing the bonding layer from being damaged are bonded to each other. The durability and the efficiency of the operation of the electrostatic chuck device are improved.