The family Scelionidae is distributed all around the world, which has approximately 3,000 species within 150 genera in the world. To date 39 species of 15 genera from 3 subfamilies in Scelionidae are recorded in South Korea. In this study, we report a new record of the genus Idiris with one species. There are many parasitory and predatory insects specializing on spider eggs. Among scelionids, some species (Baeus achaearneus, Comastichus zopheros, Idris sp.) parasitize spider eggs. However, there was no Korean record for scelionid wasps parasitizing in egg sacs of spider. Based on morphology, ecology, and DNA identification, we recognized this species, Idris sp., being new to Korea. All examined specimens and DNA samples are deposited in Kunsan National University.