To provide a laser displacement gage capable of measurement by receiving only reflected light from the surface or the back of a transparent measuring object without narrowing a measuring range.

This displacement gage is equipped with a floodlighting part 20 for irradiating a transparent body 40 with laser light, a light receiving part 30 for receiving reflected light from the transparent body 40 in the direction different from the irradiation direction of the laser light, and forming an image of an irradiation point on the transparent body 40, an imaging position detection element 31 having the light receiving surface arranged on the imaging position of the irradiation point by the light receiving part 30, for outputting a signal corresponding to the imaging position of the irradiation point, shielding masks 33, 34 arranged on the light receiving surface side of the imaging position detection element 31, for restricting a light receiving range of the reflected light by the imaging position detection element 31, and a shielding mask moving means 300 for moving the shielding masks 33, 34 along the light receiving surface in the state where the restricted light receiving range is maintained.