A method and an apparatus for manufacturing a reaction bonded silicon carbide by the infiltration of molten metal by using a porous silicon carbide/carbon or carbon preform in which the molten metal is supplied to the carbon preform by capillary action through a pyro-carbon coated dense graphite feeder on which a transfer path of molten metal is defined from a molten metal supplier under an inert atmosphere, and a carbon woven fabric on which the carbon preform is placed transfers continuously the carbon preform at a constant speed and thereby infiltrates the carbon preform. The apparatus and method for manufacturing a reaction bonded silicon carbide which enable mass production of goods of various sizes and characteristics by continuously transferring the carbon preform on the carbon woven fabric and supplying the molten metal through the pyro-carbon coated graphite feeder.