There is provided a small multi-band antenna that is capable of supporting multiple bands. A first sub-element (11) is disposed at a region where strength of electric field becomes relatively large while power is being fed on a main element (10) capable of irradiating a high-frequency signal of a plurality of frequency bands, and a second sub-element (12) is disposed at a region in which strength of electric field becomes relatively small while power is being fed on the main element (10). Then, the first and second sub-elements (11) and (12) are operated as passive reflective elements by putting one end portions of the first and second sub-elements (11) and (12) into an electrically open state by inputting a control signal of a first level to a switching mechanism (14), and are operated as electrically short-circuit elements that couple in high frequency with the main element (10) by grounding one end portions directly or via a predetermined resonance circuit by inputting the control signal of a second level. Thus, the high-frequency signal irradiated from the main element (10) is switched to any one of the plurality of frequency bands.