Laser Induced Breakdown Spectroscope (LIBS) instrument flown in Chandrayaan-2 mission to the Moon, is one of the scientific instruments on the Pragyaan rover. It is primarily developed to carry out in situ investigations for the elemental composition study of lunar regolith and pebbles on the Moon surface in a previously unexplored high latitude area in the southern polar region. A pulsed laser source, a set of optical lenses and mirrors, an aberrationcorrected concave holographic grating and a linear detector, are the principal electro-optical accessories of the instrument. The developed LIBS is a lightweighted (~1.1 kg) and low power consuming (≤1.2 W) compact instrument. This paper presents the system engineering and development aspects of the LIBS instrument along with results from environmental tests. Performance evaluation of the instrument during endto- end testing is satisfactory and within desired specifications. Details on ground calibration techniques used to evaluate the instrument capability are also presented.