In order to effect the reading-out of a signal from a recording medium at a high speed and without the collision of a probe electrode, the control of the spacing between the probe electrode and the signal recording layer of the recording medium is effected by sampling a tunnel current detected by the probe electrode at the timing of a reproduction clock, and reproduction is effected with this sampled value as a reference. Also, in order to effect information recording with good reproducibility and at high density, the control variable of a servo control circuit for controlling the spacing between the probe electrode and the recording layer is changed over during the periods before and after a writing pulse is applied to the probe electrode. Also, in order to effect re-recording reliably, the prior recorded state at the re-writing position is detected, and from the result of this detection, an optimal servo control variable, the waveform of a pulse voltage applied, etc. are set.