Abstract: An apparatus for examining the electrochemical effects of (in vivo) metal implants causing allergic symptoms and/or inflamation in living organism, the apparatus containing two probes and a signal processing circuit connected thereto. One of the probes is a reference electrode (1) provided with reference electrolyte (34), which is connected to the soma tissue near the implant while the other probe is a measuring electrode (2) provided with a metal contact tip (6) to be contacted with the implant. The reference electrode (1) and the measuring electrode (2) are connected through an amplifier (20, 27) to one of the inputs of a comparing unit (22, 28). The other input of the comparing unit (22, 28) is connected the output of a memory (24, 30) containing data concerning the metal to be examined, and one of the outputs of the comparing unit (22, 28) is connected the display for the measured data (11).