Antenna device

An antenna device comprising:

• an antenna substrate;
• an antenna element including an antenna unit that is arranged at a position separated by a predetermined length in a first direction that is perpendicular to a substrate surface of the antenna substrate from the substrate surface, in such a way as to be parallel to the substrate surface of the antenna substrate, and a grounding unit that is connected continuous to the antenna unit and electrically connected to the antenna substrate;
• a first case having electrical insulating properties and forming a part of a housing that houses the antenna element;
• and
• a columnar holder that is elongated in the first direction and fixed to the antenna substrate to thereby hold the antenna unit, wherein
• the antenna unit is formed with a fitting hole that penetrates in the first direction,
• the holder is formed with a fitting protrusion that is fitted into the fitting hole, and
• in a state in which the antenna element is housed in the housing, the fitting protrusion penetrates into the fitting hole to abut on an inner surface of the first case.