In this paper, developed wireless portable infrared pyrometer with dual channel fiber optic is described. The pyrometer measures surface temperature in wide infrared spectral range of 2 - 25 um. A data processing algorithm based on the methods of synchronous detection providing accuracy <0.1°C within the range of 10°C - 50°C and with time constant of 1 sec was developed. Flexible fiber optic allows measuring the temperature in difficult-to-access places.