There is provided a technique for suppressing increase of SAR without sacrificing sensitivity in RF coils used in MRI apparatuses. The present invention provides an antenna device comprising a sheet-shaped conductor and a ribbon-shaped conductor disposed on the subject side with respect to the sheet-shaped conductor with a predetermined distance from the sheet-shaped conductor. The ribbon-shaped conductor has a meandering shape, and is adjusted so as to resonate at transmission and reception frequencies, and it is constituted so that distance to the sheet-shaped conductor becomes smaller at both end part thereof along the static magnetic field direction compared with the distance to the sheet-shaped conductor at the center thereof. Moreover, the ribbon-shaped conductor is constituted so as to have a smaller width, as the distance to the sheet-shaped conductor becomes smaller.