A brominated flame retardant determining method, comprising steps of: emitting light to a determination target object composed of resin; receiving reflected light from the determination target object emitted with the light; calculating an absorption spectrum of the determination target object based on the reflected light; and determining (S5, S13a) whether or not a brominated flame retardant is contained in the determination target object based on, in the absorption spectrum, an absorption spectrum in at least one of wavelength bands including a wavelength band of 1.42 μ m or more and 1.44 μ m or less, a wavelength band of 1.45 μ m or more and 1.47 μ m or less, a wavelength band of 1.66 μ m or more and 1.68 μ m or less, a wavelength band of 1.72 μ m or more and 1.74 μ m or less, a wavelength band of 1.92 μ m or more and 1.94 μ m or less, a wavelength band of 2.11 μ m or more and 2.12 μ m or less, a wavelength band of 2.17 μ m or more and 2.20 μ m or less, and a wavelength band of 2.31 μ m or more and 2.34 μ m or less, wherein the step (S5, S13a) of determining whether or not the brominated flame retardant is contained in the determination target object, comprises: determining a type of the resin of the determination target object; characterized in that when the result of the determination of the type of the resin of the determination target object is ABS resin, determining (S13a) as a first priority, the wavelength band of 1.42 μ m or more and 1.44 μ m or less, and as a second priority, the wavelength band of 1.45 μ m or more and 1.47 μ m or less; and determining whether or not the brominated flame retardant is contained in the determination target object based on an absorption spectrum in the wavelength in accordance with the determined priorities of the wavelength bands. emitting light to a determination target object composed of resin; receiving reflected light from the determination target object emitted with the light; calculating an absorption spectrum of the determination target object based on the reflected light; and determining (S5, S13a) whether or not a brominated flame retardant is contained in the determination target object based on, in the absorption spectrum, an absorption spectrum in at least one of wavelength bands including a wavelength band of 1.42 μ m or more and 1.44 μ m or less, a wavelength band of 1.45 μ m or more and 1.47 μ m or less, a wavelength band of 1.66 μ m or more and 1.68 μ m or less, a wavelength band of 1.72 μ m or more and 1.74 μ m or less, a wavelength band of 1.92 μ m or more and 1.94 μ m or less, a wavelength band of 2.11 μ m or more and 2.12 μ m or less, a wavelength band of 2.17 μ m or more and 2.20 μ m or less, and a wavelength band of 2.31 μ m or more and 2.34 μ m or less, wherein the step (S5, S13a) of determining whether or not the brominated flame retardant is contained in the determination target object, comprises: determining a type of the resin of the determination target object; characterized in that when the result of the determination of the type of the resin of the determination target object is ABS resin, determining (S13a) as a first priority, the wavelength band of 1.42 μ m or more and 1.44 μ m or less, and as a second priority, the wavelength band of 1.45 μ m or more and 1.47 μ m or less; and determining whether or not the brominated flame retardant is contained in the determination target object based on an absorption spectrum in the wavelength in accordance with the determined priorities of the wavelength bands. determining a type of the resin of the determination target object; characterized in that when the result of the determination of the type of the resin of the determination target object is ABS resin, determining (S13a) as a first priority, the wavelength band of 1.42 μ m or more and 1.44 μ m or less, and as a second priority, the wavelength band of 1.45 μ m or more and 1.47 μ m or less; and determining whether or not the brominated flame retardant is contained in the determination target object based on an absorption spectrum in the wavelength in accordance with the determined priorities of the wavelength bands.