Abstract: Disclosed is a hands-free signal processing device in a mobile communication terminal. More particularly, disclosed is a hands-free signal processing device in a mobile communication terminal, which may separate hands-free signals, such as a microphone signal and an interrupt signal generated in a hands-free device, by using transistors, and properly process the hands-free signals. According to the present invention, current consumption caused by a hands-free device can be minimized by converting AUX_MIC signal into pulse and by using the pulse as a reference pulse of the hands-free device. Further, a talk-key interrupt signal of a hands-free device can be correctly detected while incoming/outgoing calls are connected. Thus, a problem in timing can be solved and a proper reaction to the talk-key interrupt signal of a hands-free device can be achieved.