A compressor is disclosed. The compressor includes an upper shell and a lower shell forming an appearance of the compressor. The compressor also includes a coupling portion provided between the upper shell and the lower shell and configured to protrude from a side surface of the upper shell or the lower shell to outside the upper shell or the lower shell. The coupling portion includes at least one coupling protrusion configured to protrude from a side surface of a flange portion to the outside, to increase a rigidity of the flange portion and the coupling portion.