In a previous study, the authors have developed a ground corrosion sensor to evaluate the corrosivity of steel members near the ground. This research aimed at the fundamental investigation of the output properties and practicality of a ground corrosion sensor. The output characteristics were verified by two electrochemical tests. The corrosion rates were evaluated using sensor measurements and indoor exposure tests by simulating NaCl aqueous solution environments, which contain air-liquid interfaces. Besides, the actual corrosion depths obtained from the exposure tests were compared with those estimated by the sensor. Moreover, an evaluation method for time-dependent corrosion depth prediction of steel members using the corrosion sensor was proposed.