Disclosed is a calcination apparatus, including: a calcination tube having open ends at both terminals; a pair of hoods, each hood covering each open end of the calcination tube; and a pair of rings, each ring sealing a gap between the calcination tube and the hood, wherein the rings are directly or indirectly fixed on an outer surface of the calcination tube; a groove is provided along a circumferential direction of the ring at a contact surface side between the ring and the hood; a sealed chamber surrounded by the hood and the groove is formed; and both the calcination tube and the rings rotate in a circumferential direction of the calcination tube while keeping the hood in contact with both sides of the groove.