PURPOSE: To provide a simple heater convenient in carrying by providing a metal net with a flat face that covers the whole bottom face of a specific solid fuel and at the same time providing standing-up sections that stand to a uniform height at at least opposite sections around this flat face.

CONSTITUTION: At first, a metal net B and bag C are taken out of a box D, and then the bag C is put away from the metal net B and a solid fuel is taken out of the bag C by breaking it. After this, the standing-up section 24 of the metal net B is made to face downwards and the flat face section 23 in the center is positioned in the upper section. When solid fuel A is put on the flat face section 23, because of the uniform height of the standing-up section 24, the metal net B supports the solid fuel A stably, and a space is formed below the flat face section 23. An ignition fire should be placed in the space formed by the metal net B in order to ignite a simple and convenient heater. As the ignition fire only a match stick that is lighted can be placed. For surer ignition, if pieces of newspaper waste or small pieces of the box D are burned in the space, the solid fuel A can be ignited easily because its main ingredient is carbon powder and it burns. During the combustion of the solid fuel A, air flow is good because it is supported on the metal net B, and the solid fuel continues to burn until it is completely burned out.