An antenna device capable of suppressing influence on an antenna performance even if an electronic device is provided in its vicinity is provided. An antenna device 1 is equipped with a top element 30 and a coil 40. A casing 51 of a camera 50 is disposed at such a position as not to be right under the top element 30. The coil 40 is disposed close to the casing 51 in a front-rear direction. A distance between the casing 51 and the coil 40 in the front-rear direction is longer than or equal to 0.00075 times a shortest wavelength of a reception target signal. A maximum antenna efficiency of the antenna device 1 in a predetermined frequency band is higher than or equal to 85% of a maximum antenna efficiency in a case where the camera 50 is not provided.