To improve the rigidity of the entire card by integrating the circuit part and antenna part of a radio LAN card by a metallic case, to compact the card by equalizing a thickness of both parts and to constitute a slot antenna by a slot directly provided on a case surface.

A card outer shape is formed by covering the circuit part and the antenna part by an integrated metallic case, power is fed from a microstrip line provided on a printed board to the slot provided on the surface on the antenna part side of the case and the slot antenna is formed. Also, inside the case, the circuit part and the antenna part are separated by a block for radio interference prevention.