To provide a sighting system for surveying instrument use which is high-precision and allows easy sighting even by its small size.

The sighting system for surveying instrument use (30) includes an optical sighting device (8) and a rear sight (34) arranged on an optical axis (20) at the rear of the optical sighting device. The rear sight is provided at the rear end of a body tube protruding part (32) protrudingly provided backward from the optical sighting device.