Electron holography, which visualizes a local magnetic and/or electric field, is a hopeful experimental tool in explorations of complex magnetic microstructures in advanced materials. The aim of this review article is to present the essence of electron holography and its applications to current issues about the magnetic microstructure in a perovskite-type manganite La1-xSrxMnO3, which has captured attentions of many researchers because of the peculiar magnetoresistive properties.