PURPOSE: To enable the manufacturing of the high quality title coke in large quantity, using a single-stage shaft oven, by hardening the surface of specific briquette coal at rapidly at the initial stage of the carbonization.

CONSTITUTION: Coal briquettes manufactured by mixing powdered coal with a binder, and having a water content of ≤3% and a porosity of ≤13%, is charged into a heating oven and heated from room temp. at a heating rate which gives the average heating rate of a briquette coal having a volume of 25W120 ml of 5W40°C/ min. The heating rate is averaged from the charge of the briquette to the time at which the temperature at the center of the briquette reaches 200°C. The heating rate of a larger briquette becomes slower. By this heating process, the temperature gradient in the briquette is decreased, the softening and melting zone of the briquette is widened, and the caking property of the briquette is improved. Furthermore, the carbonized surface layer is thickened within the temperature range in which the binder softens, which improves the crush resistance and gives high quality metallurgical coke having the original form of the coal briquette.