A wireless commutation device includes: an antenna unit including antennas transmitting and receiving wireless signals; an analog processing unit including transmitting analog circuits and receiving analog circuits processing analog transmitting and received signals; a digital processing unit processing digital transmitting and received signals; an inter-antenna propagation loss determination unit determining propagation losses between the antennas; a loopback transfer function gain acquisition unit acquiring, through loopback of a calibration signal between the antennas, gains of loopback transfer functions between antenna branches; a loopback transfer function gain correction unit correcting the gains by using the propagation losses; a correction coefficient determination unit determining the respective gain ratios among the receiving analog circuits and the transmitting analog circuits by using the corrected gains, and determining correction coefficients by using the gain ratios; and a gain calibration processing unit performing gain calibration on the digital transmitting and received signals by using the correction coefficients.