To provide a solid fuel capable of giving strong heating power, by supplying the solid fuel with an enough amount of air so as to be completely burnt, when it is used as a portable fuel.

This solid fuel 5 has such a structure that a hole 6 is bored at the center and is encapsulated in a combustible film. When a projection of a burner which is so structured that it has two or more air-inflow ports in a peripheral area thereof and the projection for fastening the solid fuel at the center of an inner space thereof is inserted into the hole of the solid fuel so as to set the solid fuel, the solid fuel is always correctly set at the center of the burner, so that the solid fuel is uniformly supplied with the air (oxygen) from every direction and therefore is completely burnt.