Abstract: A thermal insulation material can suitably be used as a thermal insulation material for a hot press, a rubber vulcanizing machine, and an injection molding machine, a casing for an induction furnace, and the like, and exhibits good workability, excellent heat resistance, excellent mechanical strength, excellent toughness, excellent working accuracy, excellent thickness accuracy, and the like. The thermal insulation material is produced by hot-pressing a plurality of prepregs in a state in which the plurality of prepregs are stacked, each of the plurality of prepregs being obtained by impregnating heat-resistant paper with a thermosetting resin, the thermal insulation material including 32 to 64 mass % of a fibrous material and 36 to 68 mass % of the thermosetting resin.