PURPOSE: To prepare a grilled egg capable of keeping the freshness of an egg with egg-shell for a long period, by keeping a fresh egg with egg-shell at specific two temperature ranges for longer than specific periods during the heating of the egg to a specific temperature at a specific rate of heating, and cooling the heat-treated egg.

CONSTITUTION: A fresh egg with egg-shell is heated from room temperature to 150±10°C at a heating rate of 5W15°C/min by circulating hot air or super- heated steam. In the above process, the egg is maintained at 95±10°C and 150±10°C for ≥10min each, and cooled to ≤ room temperature. A grilled egg with egg-shell which cannot be produced hitherto because of the cracking and explosion of the shell can be produced easily by this process, and consequently, an egg can be stored for a long period in a state having excellent taste, flavor and palatability and having low hydrogen sulfide odor.