An apparatus for processing a substrate includes: a process chamber providing a reaction space by a combination of a lid and a body; a susceptor in the reaction space and having a substrate thereon; a plurality of plasma source electrodes over the reaction space; a plurality of first lower protruding portions under the lid; and a plurality of first gas injecting means corresponding to the plurality of plasma source electrodes and a plurality of second gas injecting means alternately disposed with the plurality of first gas injecting means.