To stably observe the surface of a sample, without changing the state of a probe or the state of the surface of the sample, in measuring tunnel current by the scanning with the probe.

A control part 15 independently controls a first control process for controlling the driving of the probe 11 in measuring the tunnel current flowing between the sample 10 and the probe 11 and a second control process for controlling the driving of the probe 11, in the movement of the sample 10 between measurement points so as to measure the tunnel current by the scanning with the probe. Here, the contact of the probe with the sample is made avoidable.