A process of producing an aluminum/silicon carbide composite which has an aluminum alloy layer made of a metal containing aluminum as the main component on both principal surfaces, one principal surface being for bonding to a circuit plate and the other principal surface being to be utilized as a radiation surface, said process comprising the following steps, in this order: machining one principal surface of a flat silicon carbide porous preform into a convexly bowed shape or forming a flat silicon carbide porous preform with one principal surface having a convexly bowed shape, infiltrating the silicon carbide porous preform with a metal containing aluminum as the main component in order to obtain an aluminum/silicon carbide composite with an aluminum alloy layer made of a metal containing aluminum as the main component on both principal surfaces, one principal surface being destined for being bonded to a circuit plate and the other principal surface being bowed, machining the aluminum alloy layer on said bowed principal surface for imparting bow to said bowed surface in an amount of from 10 to 400 μm per 200 mm on the major axis, wherein, after said aluminum alloy layer machining step, the bowed surface is utilized as the radiation surface, the average thickness of the aluminum alloy layer on the surface for bonding to a circuit plate is from 0.1 to 0.3 mm, and the difference in the average thickness between the aluminum alloy layers on both principal surfaces is within 40% of the average thickness of the thicker aluminum alloy layer, characterized in that the aluminum alloy layer made of a metal containing aluminum as the main component contains from 5 to 40 mass% of at least one member among fibers, spherical particles and crushed particles, containing alumina or silica as the main component. machining one principal surface of a flat silicon carbide porous preform into a convexly bowed shape or forming a flat silicon carbide porous preform with one principal surface having a convexly bowed shape, infiltrating the silicon carbide porous preform with a metal containing aluminum as the main component in order to obtain an aluminum/silicon carbide composite with an aluminum alloy layer made of a metal containing aluminum as the main component on both principal surfaces, one principal surface being destined for being bonded to a circuit plate and the other principal surface being bowed, machining the aluminum alloy layer on said bowed principal surface for imparting bow to said bowed surface in an amount of from 10 to 400 μm per 200 mm on the major axis, wherein, after said aluminum alloy layer machining step, the bowed surface is utilized as the radiation surface, the average thickness of the aluminum alloy layer on the surface for bonding to a circuit plate is from 0.1 to 0.3 mm, and the difference in the average thickness between the aluminum alloy layers on both principal surfaces is within 40% of the average thickness of the thicker aluminum alloy layer, characterized in that the aluminum alloy layer made of a metal containing aluminum as the main component contains from 5 to 40 mass% of at least one member among fibers, spherical particles and crushed particles, containing alumina or silica as the main component.