ANTENNA DEVICE

PROBLEM TO BE SOLVED: To provide an antenna device which can be made compact and thin while ensuring the antenna performance according to the application, and in which each resonance frequency of double resonance can be adjusted flexibly.SOLUTION: The antenna device includes a substrate body, a ground surface GND1 formed of a metal foil on the substrate body, a first element 3 connected with passive elements P1, P5 in the way, and a ground induction pattern 4 arranged in the vicinity of the substrate body, formed of a metal foil or a metal plate and connected with the ground GND2. The first element has a first extension E1 provided with a feeding point FP at the proximal end near the ground surface and having the tip side extending from the feeding point in a direction receding from the ground surface, and a second extension E2 having a proximal end connected with the tip of the first extension and extending in the direction along the ground surface, and having an antenna element AT connected closer to the tip side than the first passive element P1. The ground induction pattern is arranged in the vicinity of the second extension and extends along the second extension.