In one embodiment, an RF coil device includes a base board, a belt member, a first coil element, a second coil element inside the base board, and a connecting unit. Both ends of the belt member are respectively connected to mutually separated places on the base board, so that the center part of the belt member is located on the anterior surface of the base board. The belt member is curved to form airspace between the center part thereof and the anterior surface for letting an arm pass through in interdigitation state. The first coil element includes first and second partial coils inside the belt member, and becomes a loop coil element by their connection. The connecting unit detachably connects the base board to the belt member, and mutually connects the first and second partial coils in the interdigitation state.