To facilitate harmless, safe processing, perform fungus-resistance processing on the inside and water-proof processing on the outside, and improve lubrication resistance by providing a heating sheet being non-magnetic, being brought in close contact with a paper pot therein and an electromagnetic device at the bottom thereof, and specifying a height, tolerance of degree of levelness, and a thickness.

A cooking utensil 2 of an electromagnetic induction heater 1 comprises three types of a paper pot 3, a heating element 4, and a protective container 5. At a circumferential contour of a bottom part of the paper pot 3, 15 to 20 folds are provided with equal intervals. Paper is 115 to 160 g/m2 and is plow-based of different two or more layers in directivity of paper fiber. The heating element 4 is a magnetic disc provided a hole for steam excavation in which a total area of a heating plate is 0.14 to 0.32. The protective container 5 is non-magnetic, is tilted to a substantially circular bottom part and to the peripheral container of that bottom part, and a rise and a height are 0.55 to 0.9 of the minimum height of the paper pot 3 upwardly. To make intimate contact with the heating element 4, internal and external faces are 0.15 mm or less in tolerance of degree of levelness, and thickness is 0.6 to 4.7 mm.