NOVELTY - The apparatus (1,1A) has filter portion (20) which removes foreign substances from edible waste oil processed by waste-oil-treatment tank (10). An edible-waste-oil transmission port (16) is provided sending-out processing-completed edible waste oil to filter portion. The water and deposit of waste oil accumulated on bottom portion (17) of tank are discharged from deposit discharge port (18). The microparticles of foreign substances are removed and biofuel is produced from waste oil after discharging water content from water vapor discharge port (12).    USE - Biofuel production apparatus of composite fuel production apparatus (claimed) used for boiler, incinerator, drying machine and generator, for producing biofuel from edible waste oil discharged from food manufacturing industry, food service industry, restaurant, hotel and home.    ADVANTAGE - Effective usage of edible waste oil can be accelerated with simple structure. The biofuel production apparatus can be manufactured with low cost by adding the flash point improvement agent to biofuel.    DETAILED DESCRIPTION - A strainer receives the edible waste oil injected from injection hole (11), and eliminates a solid substance. A heating unit is provided for heating edible waste oil inside the waste-oil-treatment tank. The stirring units (14,31) are provided for stirring edible waste oil inside the waste-oil-treatment tank. The water vapor discharge port is provided in the upper portion of the waste-oil-treatment tank. The deposit discharge port is provided for discharging outside the water and the deposit which are provided in the bottom portion. A flash point improvement agent addition portion is provided for adding the flash point improvement agent to the biofuel from bio-fuel tank (30). The storage tank is provided for storing the biofuel added with flash point improvement agent. INDEPENDENT CLAIMS are included for the following:    (1) composite fuel production apparatus which has mixing portion for mixing the biofuel and heavy oil. A composite fuel storage tank stores the composite fuel mixed in mixing portion such that the stored composite fuel is heated by heating portion; and    (2) biofuel production method which involves injecting edible waste oil into waste-oil-treatment tank and removing foreign substances through strainer (13). The filter portion is provided in the exterior of waste-oil-treatment tank for removing the microparticles of foreign substances.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of biofuel production apparatus. (Drawing includes non-English language text)    Biofuel production apparatus (1,1A)    Waste-oil-treatment tank (10)    Injection hole (11)    Water vapor discharge port (12)    Strainer (13)    Stirring units (14,31)    Edible-waste-oil transmission port (16)    Bottom portion (17)    Deposit discharge port (18)    Filter portion (20)    Bio-fuel tank (30)