Provided is a case for a portable electronic device. The case includes an outer part; an inner part coupled to an inner surface of the outer part and including a plurality of holes; and fastening members, each including a main body having an outer diameter corresponding to an inner diameter of the hole in the inner part and a flange portion, wherein the flange portion is connected to an end portion of the main body, has an outer diameter greater than the outer diameter of the main body to be depressed into the inner part.