TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Components: The apparatus further contains an intermediate tank (8) for storing the crushed material from which the foreign material is removed and the crushed material may be supplied from the intermediate tank to the secondary crusher. The primary crusher has a rotary blade provided in main component of rotating shaft and installed at multiple stages covering the axial direction of rotating shaft, fixed blade fixed in the main component and screen arranged under the rotary blade. The primary crusher is a crusher which discharges the crushed coarse through the screen with opening of 30-200 mm and during coarse crushing of combustible waste material, the velocity of rotary blade is 20-60 rpm, the phase difference of the rotary blade of the adjacent two stage is 60 degrees or less and the space interval of screen and rotary blade is 20-100 mm. The secondary crusher has a rotary blade provided in main component of rotating shaft, fixed blade fixed in main component and screen arranged under the rotary blade. The secondary crusher is a crusher which discharges the crushed coarse through the screen with opening of 5-20 mm, and during coarse crushing of combustible waste material, the velocity of rotary blade is 60-600 rpm, and the space interval of screen and rotary blade is 10-50 mm. In the conveyance surface, a screen with opening of 1-50 mm, perforated panel with hole diameter of 1-50 mm or plate-shaped material perforated with several slits with width of 1-50 mm is positioned. Preferred Conditions: The combustible waste material is crushed in major-axis diameter of 200 mm or less by the primary crusher, and the coarse crushed material from which foreign material was removed is crushed in major-axis diameter of 15 mm or less by the secondary crusher. After making the moisture content of coarse crushed material to 5 mass% or less, the coarse crushed material is supplied to crusher so that the motive power of the secondary crusher is optionally fixed. The crushed material is immediately blown into the burner after crushing. The crushed material is blown into the burner with other fuels whose amount is varied, and the heat-amount generated by combustion of crushed material and other fuels which are supplied from the burner is adjusted. The fuel-formation method further involves temporarily storing coarse crushed material in a storage unit from which required amount of crushed material is extracted and supplied to secondary crusher. The feed-rate of combustible waste material to primary crusher is controlled, based on the quantity of coarse crushed material to be stored in the storage unit. The running speed of primary crusher is controlled according to the quantity of coarse crushed material to be stored in the storage unit. The feed-rate of the coarse crushed material to secondary crusher is controlled according to the load current of secondary crusher. The air volume which induces the crushed material produced by the secondary crusher to burner is controlled according to the amount of coarse crushed material extracted from the storage unit. The volume density of the crushed material produced by the secondary crusher is 0.03-0.20 kg/L, and the average value of major-axis diameter of the crushed material produced by the secondary crusher is 3-15 mm. The crushed material is blown into the burner with air quantity of 0.4-3 Nm3/kg unit mass. While carrying out roll compression of removed foreign material and crushing inorganic substance, the thinly sliced metals are recovered by electrical-eddy-current separation apparatus.