An antenna device comprising: a first substrate extending in a first direction; a second substrate supported on the first substrate, and extending in both the first direction and a second direction orthogonal to the first direction, wherein the length of the second substrate in the first direction is less than the length of the first substrate in the first direction; and an antenna element supported on a surface of the second substrate, the surface having a normal direction substantially coinciding with the first direction, and configured to transmit or receive a wireless signal having a polarization direction substantially coinciding with the second direction; wherein the second substrate is supported on an end side in the first direction on a surface of the first substrate, the surface having a normal direction substantially coinciding with the second direction, and the antenna device further comprising: a second antenna element different from a first antenna element that is the antenna element, supported on the end side in the first direction of the first substrate, and configured to transmit or receive a wireless signal having a polarization direction substantially coinciding with a third direction orthogonal to both the first direction and the second direction; and wherein at least either the first antenna element or the second antenna element is configured as a dipole antenna. a first substrate extending in a first direction; a second substrate supported on the first substrate, and extending in both the first direction and a second direction orthogonal to the first direction, wherein the length of the second substrate in the first direction is less than the length of the first substrate in the first direction; and an antenna element supported on a surface of the second substrate, the surface having a normal direction substantially coinciding with the first direction, and configured to transmit or receive a wireless signal having a polarization direction substantially coinciding with the second direction; wherein the second substrate is supported on an end side in the first direction on a surface of the first substrate, the surface having a normal direction substantially coinciding with the second direction, and the antenna device further comprising: a second antenna element different from a first antenna element that is the antenna element, supported on the end side in the first direction of the first substrate, and configured to transmit or receive a wireless signal having a polarization direction substantially coinciding with a third direction orthogonal to both the first direction and the second direction; and wherein at least either the first antenna element or the second antenna element is configured as a dipole antenna. a second antenna element different from a first antenna element that is the antenna element, supported on the end side in the first direction of the first substrate, and configured to transmit or receive a wireless signal having a polarization direction substantially coinciding with a third direction orthogonal to both the first direction and the second direction; and wherein at least either the first antenna element or the second antenna element is configured as a dipole antenna. <EOS>