An antenna device, comprising: a first substrate; a first conductive element disposed on the first substrate to define, on the first substrate, a recessed region adjacent to the first conductive element; a second substrate facing the first substrate (SUB 1); a second conductive element disposed on the second substrate and located between the first substrate and the second substrate; a liquid crystal layer disposed between the first substrate and the second substrate; and an insulating layer disposed between the first substrate and the second substrate, wherein in a normal direction, being a thickness direction of the antenna device, the second conductive element overlaps the first conductive element and the recessed region, and the insulating layer at least partially overlaps the recessed region; the antenna device being characterized in that: the antenna device further comprises an effective region, and in the normal direction, being the thickness direction of the antenna device, the effective region overlaps the first conductive element and the second conductive element, at least one edge of the effective region is separated from a corresponding edge of the second conductive element by a distance; the insulating layer is located outside the effective region and the insulating layer comprises a first part and a second part, wherein in the normal direction, being the thickness direction of the antenna device, the first part overlaps the recessed region, and the second part overlaps the first conductive element. a first substrate; a first conductive element disposed on the first substrate to define, on the first substrate, a recessed region adjacent to the first conductive element; a second substrate facing the first substrate (SUB 1); a second conductive element disposed on the second substrate and located between the first substrate and the second substrate; a liquid crystal layer disposed between the first substrate and the second substrate; and an insulating layer disposed between the first substrate and the second substrate, wherein in a normal direction, being a thickness direction of the antenna device, the second conductive element overlaps the first conductive element and the recessed region, and the insulating layer at least partially overlaps the recessed region; the antenna device being characterized in that: the antenna device further comprises an effective region, and in the normal direction, being the thickness direction of the antenna device, the effective region overlaps the first conductive element and the second conductive element, at least one edge of the effective region is separated from a corresponding edge of the second conductive element by a distance; the insulating layer is located outside the effective region and the insulating layer comprises a first part and a second part, wherein in the normal direction, being the thickness direction of the antenna device, the first part overlaps the recessed region, and the second part overlaps the first conductive element. the antenna device further comprises an effective region, and in the normal direction, being the thickness direction of the antenna device, the effective region overlaps the first conductive element and the second conductive element, at least one edge of the effective region is separated from a corresponding edge of the second conductive element by a distance; the insulating layer is located outside the effective region and the insulating layer comprises a first part and a second part, wherein in the normal direction, being the thickness direction of the antenna device, the first part overlaps the recessed region, and the second part overlaps the first conductive element.