An antenna device includes an antenna coil including a first conductive pattern disposed on a first major surface of a magnetic sheet, a second conductive pattern disposed on a first major surface of a non-magnetic sheet, and an interlayer conductor connecting the first conductive pattern and second conductive pattern. The antenna coil including the first conductive pattern and second conductive pattern defines a spiral or substantially spiral pattern. The antenna device is a resin multilayer structure in which its base body is a laminate of the magnetic layer and non-magnetic layer and the predetermined patterns are disposed inside and outside the laminate.