Patent ID: 7353820

Claim:
A warming device comprising a heat generating main body comprising: a heat generating element; an air-permeable holding member including the heat generating element enclosed therein; and a receiving part configured to receive a part of a body being inserted, the heat generating element comprising a heat generating sheet which is prepared by papermaking, wherein an interior surface of said receiving part is formed by an exterior surface of said air-permeable holding member, the sheet contains 50% by weight or more of components other than fibrous material and contains a fibrous material including a CSF of 600 ml or less, and the air-permeable holding member includes: a first air impermeable layer disposed on first side of the heat generating element and adjacent to the heat generating element, a second air impermeable layer disposed on the first side of the heat generating element and adjacent to the first air impermeable layer, a fibrous layer disposed on a second side of the heat generating element, which is an opposite side of the heat generating element from the first side, and an air permeable layer disposed on the second side of the heat generating element adjacent to the fibrous layer.