An electron beam drawing apparatus having a grounded conductor for a screening operation in the neighborhood of a detection surface of a detector to detect a reflected electrons obtained by irradiating an electron onto a specimen and a secondary electron generated through the electron irradiation. The conductor has openings to pass therethrough the reflected electron and the secondary electron. As a result, the electric charge accumulated on an organic substance fixed onto the front surface of the detector through the electron irradiation is prevented from exerting an influence on the drawing electron beam.