Indirect dark matter search by space observation

The nature and origin of dark matter is one of the most important unresolved problem in astrophysics, since the first identification of the existence of dark matter more than 70 years ago. The most predominant candidates of dark matter are weakly interacting massive particles, which can annihilate into gamma rays, electrons and positron. These annihilated products leave a unique identifiable structure in their energy spectra. Although the current observations of gamma rays, electrons and positrons are dominated by statistical fluctuations, the ongoing and near future space observations are promising to search for dark matter. In this paper, I review indirect searches for dark matter by space observations of gamma rays, electrons and positrons, and briefly introduce near future space observations such as CALET.