The present invention provides a surveying instrument (20), comprising a surveying instrument main unit (21) which projects a measuring light to an object to be measured and measures a position based on a reflection light from the object to be measured and an operation device (67) which is removably attached on the surveying instrument main unit, wherein the surveying instrument main unit comprises a distance measuring unit (54) and (55) for emitting the measuring light and for measuring a distance, an image pickup unit (51) and (53) for acquiring an image, a reflection mirror (45) rotatably mounted and used for directing the measuring light toward the object to be measured, for directing the reflected light from the object to be measured toward a light receiving unit, and for directing the image in a projecting direction toward the image pickup unit, a detecting means (31) for detecting a rotating position of the reflection mirror, and a control unit (74) for controlling at least the distance measuring unit, the image pickup unit and the rotating position of the reflection mirror, and wherein the operation device comprises a display unit for displaying the image acquired by the image pickup unit.