An audio/video (A/V) device having a volume control function for external audio reproduction units by using volume control buttons of a remote controller is provided. The A/V device includes speakers, an audio output port for externally outputting an audio signal, an audio signal processing unit for reproducing and amplifying the audio signal and applying the amplified audio signal to the speakers or the audio output port, a memory unit for storing volume control values, and a control unit for applying to the audio signal processing unit any of the volume control values stored in the memory based on whether the external audio reproduction unit is plugged in the audio output port. The control unit controls the audio signal processing unit to adjust the volume control values for the audio output port by the volume control buttons when the external audio reproduction unit is plugged in the audio output port.