A manufacturing method of a vacuum insulation material having a core material sealed at a reduced pressure between two laminate films each having a protective layer on one side, a sealant layer on other side, and a gas barrier layer between the protective layer and the sealant layer so that the sealant layers may be opposite to each other, and a sealing part having the sealant layers fused to each other near the peripheral edge of the two laminate films so as to surround the whole circumference of the core material, wherein at least the sealing part at one side of the laminate films or the sealing part positioned in one direction of the core material out of the sealing parts surrounding the core material is heated and fused as being heated and pressed from outside to two overlapped laminate films, as seen from a section being cut off on a plane perpendicular to the closest peripheral edge, out of the peripheral edge of the laminate film, as going from the closest peripheral edge to the inner circumference of the laminate film, a pressure is applied from the protective layer to the sealant layer, so that the portion relatively increased in the compression width of the laminate film being compressed in a thickness direction on the way may be formed in a plurality of positions, and that the compression width of the portion of the laminate film compressed in the thickness direction may be changed continuously, at the same time, by heating to a temperature for fusing the sealant layer, but not fusing the protective layer and the gas barrier layer, characterized in that in a specified range not only in the compressed portion but also near the compressed portion, a part of a resin for composing the sealant layer in a portion of the laminate film compressed in the thickness direction may be moved to the sealant layer in a portion of the adjacent laminate film not compressed in the thickness direction, and thereby a plurality of thin-wall parts are formed, in which the thickness of the sealant layer between the gas barrier layer of the laminate film in one part of the sealing part and the gas barrier layer of the laminate film of other part of the sealing part is smaller than the total thickness of the thickness of the sealant layers between the gas barrier layer of one laminate film other than the sealing part and the gas barrier layer of the other laminate film other than the sealing part, moreover, at the inner circumferential side of the thin-wall part positioned at the innermost circumferential side out of the plurality of thin-wall part between two adjacent thin-wall parts out of the plurality of the thin-wall parts and at the outer circumferential side of the thin-wall part positioned at the outermost circumferential side out of the plurality of thin-wall parts, a thick-wall part is formed, in which the thickness of the sealant layer between the gas barrier layer of one laminate film and the gas barrier layers of other laminate film is greater than the total thickness of the thickness of the sealant layers between the gas barrier layer of one laminate film other than the sealing part and the gas barrier layer of other laminate film other than the sealing part, and further, of the plurality of thin-wall parts, all the sealant layers opposite to each other between two adjacent thin-wall parts are heated and fused.