Hollow structure panel for heat storage material and process for producing heat storage material panel using the same

A hollow plate-like panel comprising at least two face plates spaced apart at a given distance from each other and a core member composed of a plurality of unit cells and sandwiched between the face plates, at least one hole being provided in at least one face plate and each unit cell having at least two holes communicating with adjoining unit cells, is suitable for filling a solidifiable heat storage material to give a heat storage material panel with high strength and durability.