Typical pustular lesions of impetigo herpetiformis were examined by electron microscopy. In the upper layers of the epidermis degenerated keratinocytes and neutrophils lay close together and amorphous substances were seen within and outside the keratinocytes. Neutrophiles were not observed within the keratinocytes. The spongiform pustules of Kogoj observed with light microscopy were made up of a large number of neutrophils in a network of degenerated and stretched‐out keratinocytes. Amorphous masses of high electron density which seemed to represent highly degenerated keratinocytes were observed among neutrophil