The invention relates to the field of medicine and medical equipment； namely, to a radiometer designed for non-invasive measurement of temperature of the internal tissues of a biological object. The radiometer contains, connected sequentially, an aerial applicator contacting a biological object, a selector, a circulator installed after the selector, a receiver containing an amplifier with bandpass filters, an amplitude detector, a narrowband low-frequency amplifier and a synchronous detector, an integrator, a direct current amplifier, a reference voltage generator connected to the selector and synchronous detector. Besides, the radiometer contains a Peltier element connected to the receiver inlet, the first and second microwave loads installed on the Peltier element and having a thermal contact with it, at least one temperature sensor made with the faculty of measuring the temperature of microwave loads, wherein the first microwave load is made with the faculty of connection to the selector, the selector is made with the faculty of connecting to the first shoulder of the circulator either the aerial applicator or the first microwave load, the second shoulder of the circulator is connected to the receiver, and the third shoulder of the circulator is connected to the second microwave load. The invention provides reduced error of measurement of the internal temperature of a biological object and improved accuracy of the temperature radiometry method in detecting malignant tumors, also smaller dimensions of the instrument, better convenience of its use, and lower cost of its manufacture.
