An alignment adjusting mechanism, comprising: a probe that has a shaft and a stylus formed on a tip of the shaft; an adjusting plate having a first adjustment end and a second adjustment end which are parallel to each other in a first direction that is orthogonal to an axial direction of the shaft; a probe fixing portion integrated with the adjusting plate, the probe being fixed to the probe fixing portion; a base (20, 30, 53A, 53B) that is adapted to be connected with a measuring instrument body and that has a first base end and a second base end which are parallel to each other in the first direction; and adjustment connectors that are respectively adapted to connect the first adjustment end with the first base end and the second adjustment end with the second base end; characterized by an inclination adjuster that is adapted to press the adjusting plate in a direction parallel to a planar direction of the adjusting plate and substantially along a second direction being orthogonal to the first direction, wherein the base is adapted to be connected with the measuring instrument body and a displacement of the base in the second direction is restricted, the stylus being disposed on a line of intersection of: a first inclined surface including the first adjustment end of the adjusting plate and the first base end of the base; and a second inclined surface including the second adjustment end of the adjusting plate and the second base end of the base, when the adjusting plate is not pressed by the inclination adjuster, and inclination angles of the first inclined surface and the second inclined surface can be changed according to a displacement of the adjusting plate being pressed in the second direction by the inclination adjuster. a probe that has a shaft and a stylus formed on a tip of the shaft; an adjusting plate having a first adjustment end and a second adjustment end which are parallel to each other in a first direction that is orthogonal to an axial direction of the shaft; a probe fixing portion integrated with the adjusting plate, the probe being fixed to the probe fixing portion; a base (20, 30, 53A, 53B) that is adapted to be connected with a measuring instrument body and that has a first base end and a second base end which are parallel to each other in the first direction; and adjustment connectors that are respectively adapted to connect the first adjustment end with the first base end and the second adjustment end with the second base end; characterized by an inclination adjuster that is adapted to press the adjusting plate in a direction parallel to a planar direction of the adjusting plate and substantially along a second direction being orthogonal to the first direction, wherein the base is adapted to be connected with the measuring instrument body and a displacement of the base in the second direction is restricted, the stylus being disposed on a line of intersection of: a first inclined surface including the first adjustment end of the adjusting plate and the first base end of the base; and a second inclined surface including the second adjustment end of the adjusting plate and the second base end of the base, when the adjusting plate is not pressed by the inclination adjuster, and inclination angles of the first inclined surface and the second inclined surface can be changed according to a displacement of the adjusting plate being pressed in the second direction by the inclination adjuster.