Abstract: A corrosion measuring device is disclosed for measuring microbiologically duced corrosion using galvanically coupled electrodes exposed in an electrolytically continuous, biologically separated environment. The device consists of two, mirror image, half-cells separated by either a 0.1-.mu.m porous cellulose acetate/cellulose nitrate membrane or a solid disc. The membrane is used when measuring total corrosion current in a chemically continuous environment while the solid disc is used when evaluating individual corrosion mechanisms in chemically isolated environment. Culture medium is pumped through inlets of the half-cells at a constant speed. One of the electrodes is inoculated with viable microorganisms which colonize the electrode surface creating a corrosion current that can be measured with a zero resistance ammeter. If a solid (Teflon) disc is used, an agar salt bridge is inserted through the utility port of each half-cell to maintain electrolytic continuity.