The present invention relates to a specimen box for an electron microscope, comprising a first substrate, a second substrate, one or more photoelectric elements, and a metal adhesion layer. The first substrate has a first surface, a second surface, a first concave, and one or more first through holes, wherein the first through holes penetrate through the first substrate. The second substrate has a third surface, a forth surface, and a second concave. The photoelectric element is disposed between the first substrate and the second substrate. In addition, the metal adhesion layer is disposed between the first substrate and the second substrate to form a space for a specimen contained therein. Besides, the present specimen box further comprises one or more plugs. When the plugs are assembled into the first through holes to seal the specimen box, the in-situ observation can be accomplished by using the electron microscope.