A transmission electron microscopy (TEM) specimen holder has been developed for the measurement of the electrical resistance of a TEM sample as a function of temperature. A custom TEM heating holder was modified for this purpose. Eight feedthrough wires were passed through the specimen holder; (i) providing current to the heater, (ii) allowing for the measurement of the hot stage temperature, and (iii) enabling the measurement of the electrical resistance of the sample. This configuration creates the opportunity to directly correlate changes in the resistance to microstructural changes as a function of temperature. The working of the holder is demonstrated by studies on a phase transformation in Al–Ge films. In this way, a direct correlation was found between changes in resistance and microstructure as a function of temperature.