To maintain performance and reliability as a cold storage device by weaving very thin and slender flexible wires made of one kind of material as a longitudinal warp member and a thin wire as a lateral weft member made by coating an integrated filament composite body with a polymer synthetic fiber into a cloth-like matter.

A first thin wire d1 as a lateral weft member is constituted of a filament composite body made by integrating a plurality of filament units comprising a fiber having a specified hardness and an elasticity, and selected from tyranno fiber (R), boron fiber and zirconia fiber with a fixing agent comprising a synthetic resin or the like and coating an outer circumference of the thin wire with a polymer synthetic resin. Longitudinal warp members c1, c2 as a second thin wire is a strand made of copper, nickel, iron and aluminum having a larger specific heat per unit volume, and an outer circumference of the strand is plated with neodymium. The thin wire d1 and the thin wires c1, c2 are woven into a cloth-like matter.