It is a calibration device for a measurement instrument for measuring a compressive force or a tensile force in a longitudinal direction exerted to a linear body from a predetermined correlation. A stopper part for fixing the linear body is fixed at a one end side entrance and a push/pull movable part for enabling the linear body to be pushed and pulled in an insertion/withdrawal direction at an other end entrance is fixed, so that the relative positions of the stopper part and the push/pull movable part with respect to a sensor main body cannot be changed. A force detector measures the force in the insertion/withdrawal direction exerted from the push/pull movable part to the linear body. The force detector is interposed between the push/pull movable part and the linear body.
