To provide a magnetic field type loop antenna to which power supply can be directly performed and which can obtain high Q.

A magnetic loop antenna A is provided with an element which is looped by two turns in a square shape, wherein its intermediate part is made to be a hairpin-shaped stub 13, extending inside the loop, a frame 2 for fixing the element, a balun for unbalanced-to-balanced conversion and a capacitor aggregate 4 for switching a plurality of capacitors by a plug-in system.