NOVELTY - The infrared radiation emitter comprises a body provided with a first outer surface (8) and a second outer surface (10). The first and second outer surfaces are separated from each other. The first outer surface is designed to receive a concentrated solar radiation. The second surface is designed to emit an infrared radiation in a direction of a thermophotovoltaic cell (4). The body has a rectangular parallelepiped shape, half-cylindrical shape and a semi-circular section, and comprises a gas and/or liquid combustion chamber (12) and a channel forming the combustion chamber.    USE - The infrared radiation emitter is useful for a thermophotovoltaic system, which is useful for production of electricity by conversion of heat or heating elements.    ADVANTAGE - The infrared radiation emitter improves the performance, efficiency and reliability of the thermophotovoltaic system.    DETAILED DESCRIPTION - The infrared radiation emitter comprises a body provided with a first outer surface (8) and a second outer surface (10). The first and second outer surfaces are separated from each other. The first outer surface is designed to receive a concentrated solar radiation. The second surface is designed to emit an infrared radiation in a direction of a thermophotovoltaic cell (4). The body has a rectangular parallelepiped shape, half-cylindrical shape and a semi-circular section, and comprises a gas and/or liquid combustion chamber (12), a channel forming the combustion chamber, a core made of porous material forming the combustion chamber, and a casing made of non porous material. The combustion chamber: is fed through an outer surface of the emitter that is different from the first and second outer surfaces; extends parallel to the first and second outer surface; is adapted to be connected to a source of fuel and oxygen at one of its longitudinal ends; and comprises an array of channels to improve heat exchange between the combustion gas and the body of the emitter and a combustion catalyst. The second outer surface is opposite to the first outer surface relative to the combustion chamber. The channel extends parallel to the first and second outer surfaces. A material of the body of the emitter has a good thermal conductivity of greater than 100 W.m-1.K-1. A ratio between the second and first outer surfaces is 1.5-4. A first major face carries the first outer surface and a second major face carries the second outer surface. A convex surface forms the second outer surface. A flat surface forms the first outer surface. The first outer surface comprises a depositing material and/or has a texture adapted for improving the absorption of solar radiation and reducing its emissivity in infrared radiation. The second outer surface comprises a depositing material and/or has a texture adapted to control the infrared radiation by increasing its intensity and reducing its emissivity at high wavelength of greater than 1.7 mu m An INDEPENDENT CLAIM is included for a thermophotovoltaic system.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an emitter.    Thermophotovoltaic cell (4)    First outer surface (8)    Second outer surface (10)    Combustion chamber. (12)