Plastic porous body molding is a processing technology that intentionally forms numerous voids (pores) within plastic materials. This imparts multi-functionality, such as lightweightness, breathability, sound absorption, heat insulation, water absorption, and filtration. Representative processing methods include "foam molding" by injection molding or extrusion molding using a gas blowing agent, "sintering molding" which involves heat-fusing powders, and methods utilizing solvent extraction or phase separation. By precisely controlling pore size and pore connectivity, they are utilized as high-performance components and materials in a wide range of fields, such as filters, sound-absorbing materials, cushioning materials, medical scaffolds, and liquid-absorbing materials. The combination of material properties and molding technology is crucial.