VACUUM HEAT INSULATING MATERIAL, METHOD FOR MANUFACTURING VACUUM HEAT INSULATING MATERIAL, INSTALLATION STRUCTURE FOR VACUUM INSULATING MATERIAL, AND HOT-WATER STORAGE TANK WITH VACUUM HEAT INSULATING MATERIAL

A vacuum thermal insulation material (1) comprises a core material (3) that is formed with a fibrous member and has a core material penetrating hole (3a) formed therein; and an exterior cover (4) that has an exterior cover penetrating hole (4d) formed therein in a position corresponding to the core material penetrating hole (3a) and that covers and hermetically seals the core material (3) in a vacuum and a part of the exterior cover (4) positioned at an outer perimeter part of the core material (3) and an inner circumferential side of the core material penetrating hole (3 a) are thermally fused. The core material penetrating hole (3 a) has a first tapered section (10) formed on a first surface (3b) side of the core material (3) and has a second tapered section (11) formed on a second surface (3c) side of the core material (3). Further, an intersection part (12) between the first tapered section (10) and the second tapered section (11) is positioned on the second surface (3c) side relative to a center part with respect to a thickness of the core material (3). The angle ² of the second tapered section (11) is arranged to be smaller than the angle ± of the first tapered section (10).