3D printer is characterized by a nozzle fed by thermoplastic material and continuous fibre reinforcement, together with a mechanism with deformable members for cutting the co-extruded filament, able to create parts in composite material. Most of the additive manufacturing techniques, currently available on the market, use pre-impregnated fibres, or fibres that are impregnated ex-situ. Moreover, none of the printers allows to impregnate a reinforcement filament made of interweaving multiple fibers. The designed 3D printer enables a process of controlled interweaving of fibers with different and complementary properties. Therefore, hybrid composites with enhanced performance can be additively manufactured.