A tag device that performs high-quality radio communication without radio wave radiation or receiving characteristics being deteriorated near a person's body and without hindering communication by another IC tag. A main loop section sends and receives radio waves. The main loop section is a metal foil and has the shape of a long thin loop. The area of the main loop section is smaller than the area of a dielectric substrate. The main loop section covers part of surfaces of the dielectric substrate and part of sides of the dielectric substrate so as to put the dielectric substrate inside the loop. The main loop section is mounted in a horizontal direction of the dielectric substrate. Each of capacitive load sections is a metal foil and has a load corresponding to a capacitance component. The capacitive load sections are located at both end portions of the main loop section which covers part of the front side of the dielectric substrate and are located at both end portions of the main loop section which covers part of the reverse side of the dielectric substrate. A control unit is connected to the main loop section and controls information via the radio waves.