A relaying device includes an uplink interface that continuously receives an audio signal in communication, a wireless apparatus interface to which a repeater acting as a wireless relaying apparatus is connected, a voice buffer that buffers the audio signal, and a control unit. The control unit performs a VOX processing of detecting whether or not a level of the audio signal is equal to or higher than a preset threshold. When the level of the audio signal is equal to or higher than the threshold, the control unit starts buffering the audio signal in the voice buffer, and requests the repeater to reserve a channel. After receiving, from the repeater, a reply indicating that a channel has been reserved, the control unit reads the buffered audio signal from the voice buffer, and transfers this audio signal to the repeater.