An electronic device module includes a metallic casing having at least one boss formed therein, an electronic device unit placed inside the casing, connector terminals for external device connection electrically connected to the electronic device unit, and a metallic ground shell disposed so as to surround the connector terminals, having a front surface covered with a metal coated layer and including at least one boss insertion portion formed, a head of the at least one boss inserted into the at least one boss insertion portion and the coated layer positioned on a periphery of the corresponding at least one boss insertion portion being welded to each other to electrically connect and fix the ground shell to the casing.