PROBLEM TO BE SOLVED: To improve peel strength between a fiber layer and a foamed layer, while preventing activated carbons with especially-small grain size in a heat-generating body from being leaked from a ventilation surface of a bag body.SOLUTION: A disposable body warmer A comprises: granular heat-generating bodies 1 generating heat by oxidation reaction and a bag body 2 in which the heat-generating bodies are stored and that includes a ventilation surface 20 on at least one side thereof. The ventilation surface of the bag body includes a fiber layer 21 having communication holes 21b among fibers 21a, and a foamed layer 22 having continuous foams 22a. The fiber layer and the foamed layer include micropores 23a along the communication holes of the fiber layer and the bubbles of the foamed layer, that are formed by melting and crimping a thermoplastic resin 23 at a temperature higher than a melting point of the thermoplastic resin and lower than melting points of the fiber layer and the foamed layer.SELECTED DRAWING: Figure 1
