Apparatus for treating substrate and method for treating substrate

A substrate treating apparatus comprising:

• a chamber having an inner space and including a top wall, a bottom wall opposite the top wall, a plurality of side walls connecting the top wall and the bottom wall, a protruding wall protruding upward from the bottom wall, and a plurality of partition walls;
• a separation unit provided at the inner space and including a top plate, a plurality of side plates extending downwardly from an edge of an outer side of the top plate and facing the protruding wall, and a separation plate extending downwardly from the top plate and facing a partition wall of the plurality of partition walls, the separation unit configured to divide the inner space into a plurality of treating spaces and a transfer space;
• a plurality of support units provided at each of the plurality of treating spaces and configured to support a substrate;
• a plurality of gas supply units provided at each of the plurality of treating spaces and configured to supply a process gas to the substrate supported on the plurality of support units;
• and
• a transfer mechanism provided at the transfer space and configured to transfer the substrate between the plurality of treating spaces.