This chapter contains the current state of knowledge of additive manufacturing process known as selective laser melting (powder bed fusion by laser beam). In order to understand and know in detail the main factors that influence the performance of this manufacturing technique and the quality of printed parts, this chapter reviews the current literature about the raw material or metal powder (materials and production processes, characterization methods, recycling and reuse), the process parameters (layer thickness, scanning speed, laser power, defocusing, hatch spacing, scanning strategy), the manufacturing atmosphere, the design recommendations for manufacturing (design rules, support structures, orientation and positioning on build-plate, topological optimization), and the post-processes (mechanical, chemical and electrochemical post-processes, heat treatments).