It is an object of the present invention to provide a method for easily and economically producing an expansion-molded polypropylene-based resin article stably with a high porosity, that has continuous voids and that can be used as materials such as a sound absorbing material and a draining material. More specifically, the present invention relates to a method for producing an expansion-molded polypropylene-based resin article, in which a mold is filled with expanded polypropylene-based resin particles, and the expanded particles are heated and fused using water vapor, and then cooled, wherein expanded polypropylene-based resin particles are used in which a polypropylene-based resin having a melt index (MI) of not less than 0.1 g/10 minutes and not more than 9 g/10 minutes is used as a base resin, a cell size is not more than 150 μm, two melting peaks are present on a DSC curve obtained by differential scanning calorimetry, and β/(α+β) is not less than 0.35 and not more than 0.75 when taking a melting calorie at the lower temperature peak as α (J/g) and taking a melting calorie at the higher temperature peak as β (J/g), and a porosity of an obtained molded article is not less than 20% and not more than 50%.