Problem to be solved: to provide a highly functional clothing material with insect repellent effect, and an ultra-fine fiber sheet which has an insect repellent effect applicable to various materials.Solution: when the pest repellent 12 is contained in the spinning raw material liquid 13 as the raw material, by using a solvent containing a component having a molecular skeleton common to the pest repellent agent 12 as the solvent of the spinning raw material liquid, the spinning raw material liquid 13 of the insect repellent agent The dispersibility or solubility thereof is improved to reduce the change in physical properties of the spinning raw material liquid 13 which affects the spinning ability.Diagram【課題】防虫効果を持つ高機能性衣料材料や各種資材等に応用可能な害虫忌避効果を持つ極細ファイバーシートをもたらす。【解決手段】原料となる紡糸原料液13に害虫忌避剤12を含有させる際に、当該紡糸原料液の溶媒として害虫忌避剤12と共通する分子骨格を有する成分を含む溶媒を使用することで、害虫忌避剤12の紡糸原料液13中への分散性又は溶解性を向上させ、紡糸能力に影響を与える紡糸原料液13の物性の変化を低減させるようにした。【選択図】図2
