During audio communication between terminals, an audio quality analyzing device picks up from a network a packet containing a bit stream obtained by compression encoding of audio sent by at least one of the terminals. The device has an audio quality analyzing unit that, in addition to analyzing a header of the packet picked up, performs at least one of: an analysis of a payload header and an analysis of the bit stream contained in the payload, detects deterioration in the quality of the audio communication service, and notifies a result of the detection to an upper level device.