The switching characteristics of 4Н-SiС p-i-n diodes with 6 µm long i-region were investigated in the 20÷500 °С temperature ranges. It is shown that the diode reverse current increases with temperature and does not exceed 10-7 А at temperature of 500 °С (UR = 100 V). The diode resistance rF at forward current of 40 mA decreases as temperature increases from 20 up to 500 °С. The effective minority charge carrier lifetime in the i-region (τр) was determined from the diode switching (from forward current to reverse voltage) characteristics; it was about 5 ns. As temperature increases from 20 up to 500 °С, τр increases by a factor of 3. We discuss the possibility of application of such diodes (i) in microwave switching facilities and (ii) as temperature sensors. A comparison is made between the parameters of 4Н-SiС p-i-n diodes and those of Si p-i-n diodes with comparable values of calculated blocking voltage.