To prevent poor electrical connection of a film antenna and a circuit board.

A film antenna device 1 includes film antenna parts 10A, 10B including films 11A, 11B having an adhesive surface on one side, and antenna elements 12A, 12B formed on the films 11A, 11B, a circuit board 30 connected electrically with the antenna elements 12A, 12B, an adhesive member 40 having a first adhesive surface adhering to the circuit board 30 and a second adhesive surface adhering to the ends 13A, 13B of the film antenna parts 10A, 10B, and a case 20 for housing the circuit board 30, the adhesive member 40 and the ends 13A, 13B. Bottom case 20b of the case 20 is bonded to the adhesive surface of the film antenna parts 10A, 10B and the second adhesive surface of the adhesive member 40, and has a film antenna support 25b for pressing the film antenna parts 10A, 10B to the adhesive member 40.