The Membrane Testing Device was developed for automated, economically effective testing and validation of membranes, used in bioreactors. The automated container is divided into 3 chambers with multiple integral pressure sensors, connected to an external analyzer. During the testing process the operator receives a real-time report with a pressure chart and membrane characteristics. The flexible settings of the algorithm allows the analyzer to diagnose the clogging conditions of membranes of various types. The design of the analyzer allows testing of several membranes simultaneously.