PURPOSE: To produce a steel material having a porous surface and suitable for use as a catalyst. carrier.

CONSTITUTION: A steel material contg. ≥2wt.%, in total, of one or more among Al, Cr, Mn and Ti is embedded in a treating agent contg. 10-90wt.% powder of at least. one among Fe, Ni, Co, Si, Cu and an alloy based on one of the metals and a porous layer having ≥5μm thickness is formed on the steel material by heat treatment at 500-1,200°C to produce the objective porous steel material for a catalyst carrier. A treating agent contg. 1-50wt.% at least one of chlorides, fluorides or bromides of Fe, Ni, Co, Si and Cu may be used. This porous steel material has higher strength than t-he conventional ceramic carrier and also has function as a structural member such as a plate or tube, therefore the extension of the range of application is expected.