To provide a carbon composite material having characteristics of excellent heat resistance, light weight and excellent mechanical strength and heat insulating property, responsible as a heat insulating structural member for a press or a mold, and in particular, inexpensive and composed of materials with high environmental safeness.

A desired carbon composite material is manufactured by using ceramic fibers or wooden fibers as the matrix, combining the matrix with grains, starch or a mixture of these, further compounding an additive such as sugar to obtain a prepreg, heating and press-forming the prepreg to produce the composite material and to carbonize.