A sublimation pattern casting method capable of achieving the optimum discharge of generated gas, comprising the step of performing a casting while discharging the gas generated by the sublimation of the pattern to the outside of a mold through a discharge passage having a discharge gas suppressing means when a product is cast by filling molten metal into the mold formed by burying a synthetic resin foam body pattern in foundry sand to sublimate the pattern by the molten metal, wherein the permeability of the discharge passage is controlled based on the material and shape of the pattern and the type and temperature of the molten metal.