Abstract A prototype of the laser in vessel viewing and ranging system (IVVS) was developed at ENEA laboratories in Frascati. It is based on amplitude modulated laser radar, especially designed to withstand the severe ITER conditions. IVVS (in vessel viewing system) probe was designed and built in order to perform sub-millimetric amplitude and range images inside ITER during maintenance procedure. The paper describes the first results of the characterization of the IVVS probe under room conditions at Frascati Labs. The characterization was performed on a full-scale mock-up of the first wall panel and divertor vertical target. The surfaces of these components are considered to be typical for several in-vessel components. Furthermore, the paper discusses and describes new developments expected to increase the overall IVVS performance and functionality.