Provided is an antenna that can facilitate favorable communications even if no metal body is located near the antenna and even if the antenna is located within a metal body. An antenna is characterized in that the antenna comprises: a core (11) having a plane; a coil winding part (area B) of the plane about which a coil is wound; and no-coil winding parts (areas A, C) of the plane about which no coil is wound, wherein the coil winding part is sandwiched between the no-coil winding parts in the axial direction of the coil on the plane, and the width of the plane in the axial direction of the coil is equal to or greater than the width of the plane in the winding direction of the coil.