LILIA is an experiment of light ions acceleration trough laser interaction with thin metal targets to be done at the FLAME facility, which is now running in INFN-LNF of Frascati (Rome). In the framework of LILIA, the LNS is involved in the design and construction of a spectrometer based on the Thomson's configuration in order to diagnostic the ion ejection from the laser-generated plasma. The main goal is to realize a compact system which is both very practical and optimized with regard to the mass and energy resolution of particles obtained by laser-plasma interactions. The preliminary design has to be able to analyze and resolve beams of protons and ions up the total energy of 10 MeV. However, the technical choices adopted in this prototype have to be applied for the final device concerning a challenging spectrograph able to analyze beams of 150 MeV of total energy. The magnetic and the electric part have been built and these have been assembled. The vacuum and the high voltage test have been accomplished out and also the magnetic measurements. The results will be presented and discussed. (C) 2013 Elsevier B.V. All rights reserved.