The invention relates to a process for manufacturing a porous material comprising the following steps of providing incineration clinkers, providing an aqueous binder solution comprising at least one inorganic binder and/or at least one organic-inorganic hybrid binder, mixing said clinkers with said aqueous binder solution comprising at least one inorganic binder and/or at least one organic-inorganic hybrid binder, setting said mixture obtained by heat treatment and finally recovering the porous material thus manufactured. The manufacturing process thus makes it possible to recycle and upgrade the incineration clinkers by means of the production of a porous material. The process is particularly advantageous since the porous material may in particular be obtained very rapidly and may be used as insulating material or construction material.