The invention provides a surveying instrument, which comprises a horizontal rotating unit and a measuring unit installed on the horizontal rotating unit, wherein the horizontal rotating unit comprises a driving unit for rotating the measuring unit, a horizontal angle detector for measuring horizontal angle data, a first synchronization data generating unit, a first storage unit and a first control unit, the first control unit associates the horizontal angle data with the first synchronization data and stores in the first storage unit, wherein the measuring unit comprises a distance measuring unit for performing a distance measurement, a vertical angle detector for detecting a vertical angle at a time of distance measurement, a second synchronization data generating unit, a second storage unit and a second control unit, the second synchronization data generating unit outputs second synchronization data which indicate timings of a time of acquisition of the distance measurement data and a time of acquisition of the vertical angle data, the second control unit associates the two-dimensional measurement data with the second synchronization data and stores in the second storage unit, and the horizontal angle data and the two-dimensional measurement data can be converted to three-dimensional data based on the first synchronization data and the second synchronization data.