In this paper are described the main stages of structural and cinematic synthesis and analysis, design and functional simulation regarding the mechanism of the human hand prosthesis. For the structural scheme, one uses three pivot joints only, and one movement for closing the palm. The technical project is complete. One command scheme is shown too. The functional simulation has been made in CAD and virtual reality for to identify the best solutions and to optimize the constructive solution and to use the prosthesis by human operator.