Abstract: An improved iron ore sinter for use in a blast furnace is made from a raw sinter mix comprising: iron-bearing materials; basic fluxes including a source of CaO and a source of MgO; and solid carbon-bearing material usually coke breeze, used as a heat-generating combustible. To produce the sinter, the raw sinter mix is subjected to a sintering treatment at a high temperature in order to cause the iron-bearing materials, fluxes and carbon-bearing material to agglomerate and sinter by incipient fusion; an air-cooling treatment in order to produce a hard lumpy substance having a porous cellular structure; and a mechanical treatment to break the lumpy substance into a specific size range. The improvement to the above sinter lies in that the source of MgO in the raw sinter mix exclusively consists of synthetic olivine obtained by calcination of serpentinite.