An information recording/reproducing apparatus effects recording of information by moving a probe close to a recording medium and scanning a surface of the medium parallelly with the probe, reading out information by using a micro signal obtained from a physical phenomenon occurring in the scan. The apparatus is provided with plate electrodes and a capacity detecting device. One of the plate electrodes is formed on a substrate which supports the probe. The other plate electrode is formed on a substrate which supports the recording medium. A capacity between the plate electrodes is detected by the capacity detecting device. A gap between the probe and the recording medium is controlled in accordance with the detection result.