A substrate processing apparatus including a chamber accommodating a substrate; a substrate support in the chamber, the substrate support supporting the substrate; a gas injector to inject an oxidizing gas for oxidizing a metal layer to be disposed on the substrate; a cooler under the substrate to cool the substrate; a target mount disposed on the substrate, the target mount including a target for performing a sputtering process; and a blocker between the target and the gas injector, the blocker shielding the target from the oxidizing gas injected from the gas injector.