A bidirectional displacement detector according to the present invention includes: a displacement detector which includes a first detection element and a second detection element; a base at which the first detection element is provided; an arm which is coupled to the base so as to be rotatable around an arm rotation axis extending in a horizontal direction, and at which the second detection element is provided; and a probe which is coupled to the base so as to be rotatable around a probe rotation axis perpendicular to the arm rotation axis. The probe has a contact part provided at a position away from the probe rotation axis, and a pair of abutment parts which is disposed along a direction of the arm rotation axis and on both sides with the probe rotation axis interposed therebetween and comes into contact with the arm so as to be able to be separated from the arm. Each of the pair of abutment parts is in contact with the arm from the lower side thereof and is biased upward.