A heating device capable of evenly heating a thermal recording medium without increasing the cost of the device is disclosed. The heating device evenly heats the recording surface of a thermally-reversible recording card by conducting the heat energy transferred from a heat generating member by way of a heating member, made of aluminum having high heat conductivity and high heat capacity characteristics. By this feature, it becomes possible to accurately erase the information recorded on the recording card and to use an inexpensive heat generating member as the heat generating member.