It is reasonable to expect that the well known analogy between the compounds of monovalent thallium and silver will also apply to the properties of the chromates of these substances. The results of our measurements of the thermoelectric voltage and the temperature dependence of electric conductivity of silver chromate, presented in [1] and [2], confirmed the semi-conductive character and indicated a change in the structure of this substance at 489°C. This paper gives the results of measurements of the conductivity of thallium chromate over the temperature range of 200 to 600°C, of the effect of oxygen on conductivity, and of the sign of thermoelectric voltage; further, for purposes of comparison, data obtained in the differential thermal analysis and in reflection spectrum studies. The analogy with silver chromate revealed by these measurements is surprisingly strong and holds equally well for the temperature dependence of electric conductivity as for the sign of thermoelectric voltage, and even for the change in the structure. © 1969 Czechoslovak Academy of Sciences.