Method of manufacturing silicon carbide single crystal ingot

A method of manufacturing a silicon carbide single crystal ingot in which a silicon carbide single crystal is made to grow on a silicon carbide seed crystal in an environment at a temperature of 2000° C. or higher in a crystal growing furnace, the method comprising:

• a temperature raising step of raising a temperature in the crystal growing furnace with a silicon carbide raw material and the silicon carbide seed crystal arranged therein to a crystal growing temperature;
• a single crystal growing step of maintaining the crystal growing temperature and causing the silicon carbide single crystal to grow on the silicon carbide seed crystal;
• and
• a temperature lowering step of lowering the temperature in the crystal growing furnace from the crystal growing temperature to stop growth of the silicon carbide single crystal,
• wherein the method further comprises, between the single crystal growing step and the temperature lowering step, a temperature lowering preparation step of maintaining the temperature in the crystal growing furnace at the crystal growing temperature and causing concentration of nitrogen gas in the crystal growing furnace to increase to be higher than concentration of nitrogen gas in the temperature raising step and in the single crystal growing step, and
• wherein the concentration of the nitrogen gas in the crystal growing furnace in the temperature lowering step is higher than the concentration of the nitrogen gas in the temperature raising step and the single crystal growing step.