SURVEYING INSTRUMENT INCLUDING GUIDE LIGHT IRRADIATION UNIT

The present invention relates to a surveying instrument including a guide light irradiation unit that irradiates guide light to guide a survey operator. Provided is a surveying instrument configured so that the optical axis of a guide light irradiation unit that irradiates guide light for guiding a survey operator and the optical axis of a lens barrel portion of a distance-measuring optical system become parallel to each other on a horizontal plane. The guide light irradiation unit is not disposed above the lens barrel portion that substantially matches a collimation direction but is horizontally shifted with respect to the lens barrel portion and supported by a support member that rotatably supports the lens barrel portion. The horizontal shift distance D is configured so that a horizontal distance D between the optical axis of guide light and the optical axis of the lens barrel portion satisfies tan(α/2) × Cmin > D provided that α is an irradiation angle of the guide light in the horizontal direction, and Cmin is a shortest use distance of the surveying instrument. Since the effect of the shifting disposition is negated and the guide light irradiation unit is not disposed above the lens barrel portion, the size of a housing can be held within an appropriate range, and the use range in the vertical direction can be expanded.