[en] A film-type chemical dosemeter of ionizing radiation on the basis of polymers with radiochromic additives is described. To expand working temperature range, polyphenylquinoxaline was used as a polymer, and ferrocene - as a radiochromic additive with the following component ratio, mas %: 5-20 ferrocene, 80-95 polyphenylquinoxaline. The application of the radiation dosemeter suggested permits to considerably expand the working temperature range of film dosemeters excluding the temperature influence on their readings up to 150 deg C. At that dosemeter readings don't depend on dose rate in (0.1-2)x10⁶ rad/s range and have a linear region in 5x10⁷-5x10⁸ rad range. In addition the detector is not sensitive to light and possesses stable operating properties