Topological Classification of Exceptional Points Takumi Bessho (Kyoto U.) In this presentation, we classify exceptional points. In non-Hermitian systems, energy spectra become complex and thus we can naturally introduce two different energy gaps: point gap and line gap. We classify both point-gapless phases and line-gapless phases, and we find that all the exceptional points can be identified with robust point-gapless phases [1]. Using this classification table, we find characteristic gapless structures of non-Hermitian systems in the previous studies. We also discover a novel exceptional point protected by chiral symmetry in three dimensions. [1] K. Kawabata*, T. Bessho* and M. Sato, arXiv:1902.08479 (2019) [* equal contributions; to appear in Phys. Rev. Lett.].