Food Heating Device

A food heating device comprising a heat source and a container having an exhaust vent, in which said heat source is put in said container together with a food to be heated and water is added to said container so that said heat source is reacted with said water to generate heat and to heat the food by the generated heat,

• wherein said heat source comprises:
• a bag formed by a packing material made of a base material of nonwoven fabric of which one surface is laminated with a waterproof layer, said packing material being punched with a plurality of pinholes, and
• a heat-generating composition containing aluminum powder in an amount of 40 to 60% by weight, calcium hydroxide powder in an amount of 10 to 40% by weight and calcium oxide powder in an amount of 10 to 40% by weight, enclosed in said bag,
• said packing material has a water permeable rate of 13 to 81 milliliter/min/1 cm2 measured under the following measurement conditions (1) to (4):
• (1) ion-exchanged water of 23±3° C. is used,
• (2) head of water is 27±0.95 cm,
• (3) a water permeable area of said packing material is 2.85 cm2, and
• (4) the water permeable amount (milliliter) is defined in such a manner that after an amount of the permeated water per unit time gets constant (after a variation in amount of the permeated water per 10 seconds is within 5% at least consecutive three times), an amount of the permeated water measured in any one minute during the measurement for one minute or more is converted into a water permeable amount (milliliter) using a specific gravity of the ion-exchange water of 1.000 (g/cm3).