A new test electrochemical cell is described for monitoring the steel microbiologically induced corrosion and numerical simulations were performed using finite element method to demonstrate the suitability of the device. Carbon steel concentric ring-monitoring electrochemical cells were exposed to sterile and inoculated media for acid-producing bacteria and sulfate-reducing bacteria consortia. A relationship between impedance data and microbial growth was proposed by statistical analysis based on the receiver operating characteristic curve analysis.