In the embodiment, a communication device is provided including a substrate, an antenna mounted on the substrate, a first communication unit which transmits or receives a first signal via the antenna, a terminal provided on the substrate, a signal wire one end of which is connected to the terminal, a conductor plate connected to the other end of the signal wire, and a second communication unit which transmits or receives a second signal via the conductor plate. A sum length of a line length of the signal wire and half a circumferential length of the conductor plate is equal to integral times of half the wavelength of the resonance frequency of the antenna.