Electrophysiological studies of nerve cells have long been known and have become a promising tool in basic research and drug discovery. The following thesis presents the development of an in vitro electrophysiological measuring system. In this device the action potential of electrically active cells is measured extracellularly via a microelectrode array. The biggest challenge on the measuring system is to record signals with amplitudes in the microvolt range and still obtain a signal to noise ratio, which allows an conclusions to the nervous signal. Therefore, a suitable measuring concept had to be found, which is as possible insensitive to interferences. Various amplifiers and filter stages have been developed and improved with the help of simulations. Due to its modular design, the system offers the possibility of a flexible channel expansion and further a stimulation opportunity and an impedance measurement has been integrated. The system costs could be kept relatively low. An evaluation of the measurement system has been done successfully, in the first step with a signal generator and in the second step with signals from living nerve cells.