The paper presents a measurement microsystem of parameters of impedance sensors characterized by impedance modulus in the range of 100Ω÷1GΩ. A wide frequency range (100μHz÷1MHz), especially at very low frequencies, has been achieved by the use of the DSP (Digital Signal Processing) technique. The simple construction assures low cost of the microsystem. The form of a virtual instrument has been used; the measurement module is connected via RS-232 interface to a personal computer. This solution allows using the microsystem to impedance spectroscopy of newly-developed sensors but also leads to a realization of dedicated microsystem with own display. The measurement error of impedance modulus and phase has been determined in relation to measurement frequency and measured impedance.