An object of the present invention is to provide a microcapsule for an electrophoretic display device which can suppress reduction in later contrast even when the electrophoretic display device is allowed to stand under the high temperature and high humidity condition, favorably, under the high temperature and high humidity condition for a long time (e.g. under 60.degree. C., 90% RH for 24 hours). As a means of achieving this object, a microcapsule according to the present invention for an electrophoretic display device comprises an electrophoretic fine particle and a solvent both of which are encapsulated in a shell, and is characterized in that an amount of an alkaline metal ion in the whole microcapsule is 150 ppm or smaller.