An impedance analyzing device, adapted to a testee comprising an electrode or at least one battery cell, includes a signal capturing unit, a signal adjusting unit, a signal analyzing unit, a processing unit, and a power source supply unit providing a variable-frequency voltage signal to the testee. The signal adjusting unit receiving and adjusts a variable-frequency voltage signal and the current signal to generate an adjusted variable-frequency voltage signal and an adjusted current signal. The signal capturing unit captures a current signal generated by the testee in response to the variable-frequency voltage signal. The signal analyzing unit receives and analyzes the adjusted variable-frequency voltage signal and the adjusted current signal in frequency domain to obtain a frequency domain parameter and/or a time domain parameter. The processing unit receives the frequency domain parameter and/or the time domain parameter to obtain an impedance variation characteristic of the testee.