Abstract: A skin temperature measuring apparatus for diagonising disturbance of peripheral circulation of a patient having a cold air box including a thermo regulator of low temperature. A radiation thermometer is disposed in the cold air box for measuring the skin temperature of a test section of the patient's hand. The cold air box includes a test section inserting unit through which the test section of the patient's hand is inserted into a positioning unit. The positioning unit properly positions the test section within a visual field of the radiation thermometer. A fan blows cold air to the positioned test section, thereby allowing simple and accurate measuring of the skin temperature, while avoiding unnecesary pain to the patient.