An image correlation displacement sensor for measuring a displacement component along a direction perpendicular to a target surface, with a simple configuration. The sensor may include: an illumination portion (130′) which emits illumination light; an imaging portion including at least two optical paths (A and B′) which are used to capture multiple images of a speckle field produced by the target surface (300), one of which (A) is inclined with respect to a normal to the target surface in proximity to the target surface, and an element (110′) which deflects an at least one of the optical paths (A and B′); and a processing portion (200) which measures a displacement relative to the target surface along a direction which includes a component normal to the target surface (300) in accordance with the correlation of multiple images captured in the optical paths (A) and (B′).