The invention aims at providing an infrared-ray absorption film having a low reflection factor and a high absorption ratio equivalent to those of gold black through an economical process such as ink jet printing involving the steps of printing a porous material solution and then conducting sintering without using a vacuum process. The invention provides an infrared-ray absorption film using a porous material which suitably has a pore size within the range of hundreds of nm to several μm and is formed of a metal oxide of carbon or silica, an organic/inorganic hybrid material or a meso-porous material having the composition described above. The infrared-ray absorption film is produced by applying the porous material precursor solution onto a substrate and then conducting sintering.