PURPOSE: To reduce the height of an apparatus to make a trestle low in height and lightweight, and lessen the pressure losses for sucking exhaust gas to allow a suction fan to have a small capacity.

CONSTITUTION: A pre-heater has a vertical vessel 6, cone-shaped bodies 10 which are hollow inside, have holes 11 and 12 at the tops and circumferential faces and are arranged in multiple stages in the vessel 6, and a powder raw material feeder 18 mounted on the upper part of the vessel 6. In addition, the pre-heater is provided with a suction fan 15 which sucks gas from the top of the vessel 6, a calcination furnace 2 located between the bottom of the vessel 6 and a kiln 1, and a separating cyclone 3 which is connected to the kiln 1 and blows high-temperature gas into the vessel 6 from the circumference of the vessel 6. Thereby, heat exchange can be performed in the vessel 6 having a low height, causing a trestle to be simplified, and pressure losses in the vessel 6 becomes less, allowing the suction fan 15 to have a small capacity.