PURPOSE: To prevent a survey machine from being stolen by providing key engagement part at least at either a stand part or trestle part and then performing key engagement of those other than the stand part and the trestle part and the key engagement part.

CONSTITUTION: A stand part 4 for supporting a telescope system 2 so that it can rotate freely in reference to a horizontal axis and a trestle part 6 for supporting the stand part 4 so that it can rotate freely in reference to a vertical axis are provided. The trestle part 6 is provided with an engagement part 20 for engaging a key 30 to the conically shaped side surface with less inclination. Also, the trestle part 6 is supported by a base part 22 for adjusting the inclination of the trestle part 6 and the base part 22 is mounted on a tripod 23. Then, when an operator leaves a survey machine 1, a movable wire 24 is hung to the engagement part 20 and the tripod 23 and both edge parts of the wire 24 are connected by the key 30. Therefore, even if the operator leaves the survey machine 1. only a specific person with a master key can easily remove the survey machine 1 from the tripod 23 and an exclusive survey stand, thus effectively preventing the survey machine 1 from being stolen.