A heat generating body (100, 200), a heat generating
assembly (10, 20) and a heating device. The heat generating body (100, 200) comprises a base body (110, 210), a heat generating circuit (130, 230) and a temperature measuring circuit (150, 250). The base body (110, 210) is provided with a bottom surface (115), the base body (110, 210) is provided with a heat generating area (119, 319) and an
electrode arrangement area (117) adjacent to the heat generating area (119, 319), and the
electrode arrangement area (117) is close to the bottom surface (115) compared with the heat generating area (119, 319); the heat generating circuit (130, 230) is located on the base body (110, 210), and the heat generating circuit (130, 230) comprises a heat generating part (131, 231) and a heat generating
electrode (133, 233) electrically connected to the heat generating part (131, 231), the heat generating part (131, 231) being located in the heat generating area (119, 319), and the heat generating electrode (133, 233) being located in the electrode arrangement area (117); the temperature measuring circuit (150, 250) is located on the base body (110, 210), the temperature measuring circuit (150, 250) and the heat generating circuit (130, 230) are arranged spaced apart, and the temperature measuring circuit (150, 250) comprises a temperature measuring part (151, 251, 351) and a temperature measuring electrode (153, 253) electrically connected to the temperature measuring part (151, 251, 351); and the heat generating area (119, 319) comprises a high-temperature area (119a), and the temperature measuring part (151, 251, 351) is located in the high-temperature area (119a). In an initial heating stage of the heat generating body (100, 200), the deviation between an actual temperature and a planned temperature is small.