<p>The present invention relates to firing of a pottery such as a tile which gives a deep reduction color. In a roller hearth kiln (210) having rollers (214), a burner (10) for injecting a reducing gas is provided at a portion close to an outlet in a firing zone. A gas injection opening of this burner is formed by a hole having a diameter of 1 - 5 mm or a slot having a width of 1 - 5 mm, and the burner is provided at a height of 15 - 80 mm from the article to be fired.</p>
