An MgB 2 thin film was grown on a SiN-Si substrate, with a superconducting transition temperature, T c , near 39K. At the mid-point of the transition (T= 38.24K) and at 10Hz a noise spectral density S V = 0.34nV/ √Hz was measured. The temperature noise, K n , of the MgB 2 film at different frequencies is compared to that of cuprate high temperature superconducting (HTS) thin films (with T c ~ 90 K) used currently in transition-edge bolometers. Κ n values predict that high performance far-IR thermal detectors (i.e bolometers) can be developed using MgB 2 as a thermistor.