Abstract: An antenna device has an antenna main body, a fixing member and a bolt. The antenna main body comprises an antenna element, female connectors provided at a first connector, a female screw section, and an engagement claw inserted into an antenna mount hole to make engagement with a lower side face of a roof panel. A fixing member comprises cables, male connectors provided at a second connector, the male connectors being provided to make mechanical engagement with female connectors without an electrical connection, and being connected to the cable, and a male screw section helically fitted to a female screw section, thereby tightening the female connectors, the male connectors, and a roof panel with one another. A bolt may be mounted between the male and female connectors to allow electrical connection therebetween.