The packaged microwave 4H SiC pin diode chips (with i-region length of 6 μm, mesa diameter of 80 μm and blocking voltage of 1000 V) were investigated. We studied the parameters of diode I−V curve (in particular, the diode resistance RS at forward current) and the processes of diode switching from forward current of 50 mA to reverse voltage of 15 V, as well as C−V curves, in the 20−700 °C temperature range. At a voltage of 300 V, the diode reverse current was 10 (180) μA when temperature was 600 (700) °C. At a forward current of 40 mA, the diode resistance first decreases smoothly as temperature is increased from 20 up to 300 °C, and then grows up. As temperature is increased from 20 up to 700 °C, the effective lifetime τeff grows from 7 up to 50 ns, while the diode capacitance (in the 0−40 V reverse voltage range) grows smoothly as temperature is increased from 20 up to 400 °C.