To provide a target of a non-contact extensometer suitable for being attached to a test piece to be used as a marked line for the optical displacement measurement, and especially for detecting the position without any influence of shifting and noise in the extending direction of the test piece.

This target M of the non-contact extensometer is formed by a pattern different in optical property from the surface of the test pieces, which has an elliptical edge shape taking the extension direction (longitudinal direction) of the test piece S as a minor axis and the direction (cross direction) orthogonal to the extension direction as a major axis. The center of gravity of the target M of the non-contact extensometer is obtained from a projective component in the major axis direction of the target M of the non-contact extensometer or in the direction right-angled to the direction of tensile load applied to the test piece in an image signal obtained by imaging the surface of the test piece.