Porous carbon base material, method for preparation thereof, gas-diffusing material film-electrode jointed article, and fuel cell

A porous carbon base material includes a sheet containing carbon short fibers dispersed randomly and a carbonized resin, in which the carbon short fibers are bound by the carbonized resin and the volume of pores having a pore diameter of 10 μm or less is 0.05 to 0.16 cc/g. A method for producing this porous carbon base material includes intermittently transporting a precursor fiber sheet including short carbon fibers dispersed randomly and a resin to a space between heated plates, subjecting the precursor to a heating and pressuring treatment by the heated plates while the transformation stops, carrying out the transportation of the sheet after the treatment, and then carrying out a heat treatment, to thereby carbonize the resin in the sheet.