In antenna device which is to be used in a portable radio receiver, plural loop antennas 1 and 3 which are formed along different faces of a case 9 of the radio receiver, respectively, and switching means 5 for selecting one of received signals from the plural loop antennas are disposed. Reception is performed while selecting a loop antenna having a higher received signal level. When an antenna having the directivity or the plane of polarization which are more advantageous is selected, it is possible to ensure high reception performance.