To provide a foam molded product having voids excellent in heat insulating properties, lightweight properties and sound absorbing properties and having enhanced chemical resistance and bending strength.

Styrene modified polyethylenic resin particles, which comprise a composition containing 300-1,000 pts.wt. of a styrenic resin component with respect to 100 pts.wt. of a polyethylenic resin component with a melting point of 95-115°C containing an inorganic nucleating agent and is set to a state that styrenic resin particles with a particle size of 0.8 μm or below are dispersed in the surface layers parts at least up to 5 μm from the surfaces of the particles, are impregnated with a volatile foaming agent to form foamable resin particles. The obtained foamable resin particles are subjected to foam molding to obtain the foam molded product having voids in a void ratio of 5-50%.