A wireless communication terminal device according to the present invention comprises a main body which has a built-in electronic component, a casing which houses the main body, a cover body which is detachably attached to the casing, an antenna for wireless communication which is mounted on the cover body, a pair of electrodes which are disposed on the inner face of the cover body and connected to the antenna, a pair of terminals which are disposed on the main body and make contact with the pair of electrodes, and at least two projection pieces which are formed on the inner face of the cover body near the pair of electrodes as well as on both sides with the pair of electrodes interposed therebetween and project higher than the surfaces of the pair of electrodes.