A communication module is further miniaturized to achieve an improvement in the mounting density of the communication module. A communication module includes a plug connector connected to a receptacle connector, and the plug connector has an insertion projection inserted into an insertion recess provided on the receptacle connector. The insertion projection has a board insertion portion into which an insertion end portion of a module board incorporated in the communication module is inserted formed therein, the insertion end portion is inserted into the board insertion portion, and first electrodes formed on the plug connector are electrically connected to the module board.