To simply, readily and inexpensively produce shell eggs of high added values, for example, enhanced with excellent nutritive values, good taste, contribution to health promotion for the consumers, which have been impossible with the conventional techniques, by allowing nutritive components, for example, vitamin B1 vitamin B2, niacin, vitamin C, calcium, iron component, and the like or seasoning components, for example, salt taste, soy sauce taste, dried bonito stock taste and the like to soak to penetrate into the egg white and the egg yoke in the shell eggs.

In an electric potential transformer that can increase the input voltage of 100 V up to the output voltage of 12,000-18,000 V, the one end of the secondary coil is insulated in the transformer and the other end is used as the output line. The output line is connected to the stainless steel cage that is filled with shell eggs in the immersion (penetration) tank that is placed on the stand that is insulated from the ground by means of porcelain insulators or the like and the immersion tank is charged with the alternating voltage of 250-3,500 volts and the electric current of 10-150 μA to effect the static induction treatment whereby these nutrients and seasoning components are ionized, finely pulverized and thus is penetrated into the egg white and the egg yolk in the shell eggs.