PURPOSE: To make it possible to cool a sensor with less electric power by winding a copper mesh made by weaving thin copper wires a plurality of times, and inserting a flattened cooling part between the cooling part of a refrigerator and an infrared sensor through grease containing metal powder.

CONSTITUTION: This interface is formed as follows. A copper mesh 9, made by weaving the elastic thin wires having the high heat conductivity is wound. The mesh is folded back and a cold interface 10 is formed. Metal powder grease having high heat conductivity is applied on the upper and lower surfaces. The interface is inserted between a cooling part and an infrared sensor. The minute size error between the cooling part and the sensor is absorbed by the elasticity of the mesh 9. Since the high heat conductivity material is used, the sensor can be sufficiently cooled. In the cross section of the mesh 9, longitudinal and lateral raw element wires are crossed. Therefore, the contact area becomes large, and the thermal conductivity becomes excellent.