Device for the measurement of biological activities and/or physiological magnitudes, includes a measuring cell, equipped with a chamber suitable to receive micro-organisms to be analyzed, and one or more probes opening into the chamber. The probes are connected to measuring resources and resources for processing the electrical signals emitted by the probes. The measuring cell includes a vertical well, equipped in its lateral wall with holes uniformly distributed around the well in order to allow the probes to open into the well. The probes are sealingly attached to the well, and rest in the support resources, and suitable to receive a cup whose cross section is homothetic to the section of the well. The cup is equipped on its lateral wall with holes which are located opposite to the holes of the well when the cup is positioned in the well.