Abstract: There is provided an infrared detection device including an infrared detector and a fixing tool. The infrared detector includes an infrared detection element and a metal case. The fixing tool includes a first plate, a second plate, a third plate, and an amplification substrate. The infrared detector is held by the first plate and the second plate. The second plate is electrically connected to the third plate. The third plate is electrically connected to an analog ground portion of the amplification substrate. A potential of the metal case is the same as an analog ground potential of the analog ground portion of the amplification substrate.

Abstract: A resin is irradiated with an infrared ray, and a reflected ray from the resin irradiated with the infrared ray is received. In a reflection or absorption spectrum obtained by the reflected ray, a difference of a reflection intensity in a spectrum between a first wave number band of 1340 cm?1 to 1350 cm?1, inclusive, and a second wave number band of 1300 cm?1 to 1340 cm?1, inclusive, is calculated. It is determined whether or not a specific bromine-based flame retardant is contained in the resin, by using the calculated difference of reflection intensity in the spectrum.