Abstract: A method for fixing a window member having a layer of electrically conductive material to a can of an infrared detector over an incident opening extending through a surface of the can is performed by adhering the window member to the can with a non-conductive adhesive applied between an end surface and a side circumferential surface of the window member and a surface of the casing while leaving a portion of the side circumferential surface, formed by the electrically conductive material layer, partially exposed, masking an opposing end surface of the window member and then covering the result with a thin film of electrically conductive material part of which extends between the exposed side circumferential surface of the electrically conductive material layer of the window member and the surface of the can. Finally, the mask and the portion of the thin film of electrically conductive material covering the mask are removed.