Abstract: The present invention provides a method of manufacturing an exfoliated graphite/phenol resin composite foam of a porosity of 50-95%, a density of 0.1-0.8 g/cm3, by forming under contact pressure or reduced pressure at a temperature of 140-200° C. a mixture comprising 100 parts by weight of powdered and/or crushed exfoliated graphite and 40-240 parts by weight of phenol resin; an exfoliated graphite/phenol resin composite foam obtained by the method; and a method of obtaining an exfoliated graphite/glassy carbon composite foam of a porosity of 50-95%, a density 0.1-0.8 g/cm3 with volumetric baking shrinkage of 10% or less by baking the exfoliated graphite/phenol resin composite foam.