Abstract: Each of a mobile communication terminal (100) and a headset (200) in the present invention measures the distance to another wirelessly connected device and determines whether the other device is lost. According to the present invention, the mobile communication terminal (100) in a headset system having a loss prevention function comprises: a first communication module (110) for forming a communication channel with the headset (200); a first breakaway analyzing unit (120) analyzes whether the headset (200) breaks away at a standard distance loss from a location of the mobile communication terminal (100) by analyzing a sensitivity signal delivered via the first communication module (110); and a first breakaway warning unit (140) for warning a user of a breakaway by using at least one of a vibration signal, a sound signal, or an image signal when analysis reveals that the headset (200) has broken away at the standard distance loss from the first breakaway analyzing unit (120).