Abstract: Binder for the additive production of manufactured items, in particular made of conglomerate, adapted to be distributed on a layer of inert granular material in order to form a rigid matrix incorporating the granules of the inert granular material. The binder according to the invention is a substantially inorganic hydraulic binder with magnesium phosphate cement base. Also forming the object of the present invention is a process for the additive production of manufactured items by means of the use of the aforesaid binder and the use of a hydraulic binder with magnesium phosphate cement base as binder in the additive production of manufactured items.