It is an object of the present invention to provide a significantly beneficial specimen holder which allows mounting one or more specimens, for example, a specimen to be examined and a standard adjustment specimen for aberration correction in one specimen holder at the same time, thereby observing each specimens. The present invention is a specimen holder having a specimen holder movement mechanism for driving the specimen holder, wherein the specimen holder movement mechanism makes it possible to move the specimen holder approximately along the longer side of the specimen holder. In a preferred embodiment of the specimen holder according to the present invention, the specimen holder is characterized in that the specimen holder movement mechanism makes it possible to vary an insertion depth of the specimen holder into a tube for holding the specimen holder, with no relation to another specimen holder movement mechanism set for driving the specimen holder approximately along the longer side of the specimen holder.