To provide a small antenna which has its reception gain increased with a simple constitution and receives a signal with high sensitivity.

An antenna main body 23 is composed of a planar antenna substrate 39 made of a dielectric and antenna elements 40 provided to the antenna substrate 39. Each antenna element 40 is provided with a parasitic element between a couple of mutually isolated microstrip lines so that the microstrip lines and parasitic element have electromagnetic resonance; and the antenna elements 40 are connected sequentially through the microstrip lines and the antenna main body 23 is arranged nearly vertically and supported freely rotatably on a longitudinal axis.