<p>A microwave plane antenna wherein an antenna body including a plurality of conductive micros-trip lines covered with a plastic film and a polyolefin series dielectric layer provided along the microstrip lines for lowering SHF band transmission loss while elevating reception gain is enclosed in a plastic cover, whereby the antenna body low in the transmission loss but poor in the weatherproofness can be protected and the entire plane antenna is made utilizable reliably for long.</p>
