A communication antenna device for use in radio communication between a moving body and an access point comprises an antenna main body for transmitting and receiving a signal, a base side member of the moving body for supporting the antenna main body, and a damping mechanism provided between the base side member and the antenna main body and suppressing high frequency vibration of the antenna main body that has an impact on the radio communication. The damping mechanism includes an elastic member for absorbing high frequency vibration that has an impact on the radio communication. The elastic member has such characteristics as absorbing high frequency vibration of the antenna main body that makes changes in amplitude or frequency of a transmission signal from the antenna main body to the extent of inducing a demodulation error when the transmission signal is received at an antenna of the other party.