Disclosed is a holder device for an electron microscope, which efficiently collects light emitted when electrons collide with a sample inside the electron microscope and is selectively usable in various electron microscopes since it can be easily attached to and detached from the electron microscopes. The holder device includes a frame; a sample support block configured to be supported on the frame and comprising a sample mounting portion to support an edge of a sample; a mirror unit configured to comprise an upper mirror and a lower mirror respectively arranged above and below the sample and reflect light radiating from the sample, which is mounted to the sample mounting portion and to which an electron beam is emitted, in a predetermined direction; a condensing lens configured to condense light from the mirror unit on a predetermined target; and an optical fiber configured to collect light from the condensing lens.