To sense the heating temperature of a non-step part and to perform temperature control suitable for roasting cooking by forming a stepwise projection part on the bottom surface center part of a roasting tray made of an iron plate so as not to be in surface contact with a temperature sensor.

For this roasting tray 1 whose cross section is cap-shaped for which a raised part 2 is formed on the periphery, the stepwise projection part 4 is formed at the center part of a bottom surface 3 and the projection part 4 is constituted so as not to be brought into surface contact with the temperature sensor of an electromagnetic cooker 6. Thus, since the bottom surface 3 of the roasting tray 1 for generating heat by electromagnetic waves A of the electromagnetic cooker 6 is heated, a heating difference is generated between the projection part 4 and the non-step part 5 of the same bottom surface 3, the projection part 4 is heated mainly by the heating temperature of the non-step part 5 and the temperature sensor of the electromagnetic cooker 6 is made to perform sensing and operations by the heating temperature B, the roasting cooking is performed by the heating temperature of the non-step part 5. Then, since it is sufficient to form the bottom surface part of a roaster to a plane so as to correspond to the electromagnetic cooker, this roasting tray for the electromagnetic cooker is easily produced regardless of the plane of the roaster being round, square or rectangular, etc.