[Problem] To provide a production technique for an edible egg that contains a sufficient amount of ergothioneine by using the biological accumulation of ergothioneine in eggs, and that has antioxidative activity. [Solution] This ergothioneine-containing egg is obtained from a hen raised by being fed a hen feed for a prescribed time period, the hen feed being manufactured by manufacturing an ergothioneine-containing liquid extract from a waste medium used in the production of edible mushrooms and mixing a prescribed amount of the liquid extract into a normally used chicken feed.
