PURPOSE: To provide titled molded product of high compressive rigidity, and low compressive permanent strain and water-absorptivity, having such a crystal structure as to show both specific peak and a higher-temperature peak in the DSC-curve obtained by a differential scanning colorimetry under a specific condition.

CONSTITUTION: A polypropylene resin (pref. ethylene-propylene random copolymer) is incorporated with water, volatile foaming agent, and dispersant, followed by preliminary expansion (on heating up to the melting completion-temperature), then carrying out an in-mold expansion molding to obtain the objective product. Using a differential scanning colorimeter, 1W3mg of said product is elevated in temperature to 220°C at a rate of 10°C/min to obtain a DSC-curve, followed by temperature drop to 40°C at the same rate, then again raising temperature to 220°C at the same rate to obtain another DSC-curve. The first and second DSC-curves will show, respectively, both specific and a higher-temperature peaks and a specific peak. The temperature difference between the second specific peak and the first higher-temperature peak is pref. ≥10°C.