1. Some persons have objections to pasteurized milk because the heat used in pasteurizing it decreases the amount of vitamin C and vitamin B1 in the milk and destroys the useful lactic acid bacteria.

2. The present invention provides a method of pasteurizing an in−shell chicken egg comprising measuring the lowest temperatures of albumen and yolk on time and their location according to a prescribed method, and maintaining the lowest temperatures at the pasteurization temperature or higher for the necessary time.