There is provided a prober including inspection rooms. Each of the inspection rooms includes: a probe card having probes; a chuck top configured to mount a wafer; and a temperature adjuster configured to adjust a temperature of the chuck top. At least one of the probe card and the chuck top includes a gap adjustment member configured to maintain a constant gap between the probe card and the chuck top. The probe card is preheated by heat of the chuck top whose temperature is adjusted by the temperature adjuster, in a state in which the wafer is not mounted on the chuck top and in a state in which the probe card and the chuck top are connected with each other via the gap adjustment member.