Using 3D particle data from GEOTAIL, we have studied the occurrence of highly-collimated bidirectional electrons in the magnetotail at -50≤XGSM≤-9 Re during quiet intervals. They are found to appear frequently in the near-Earth plasma sheet (-20≤XGSM≤-10 Re), and more frequently on the dawn side than on the dusk side, with the maximum occurrence frequency of about several percentage. Both parallel/anti-parallel components possess a characteristic flat-top/bump shaped spectrum, which extends upto several hundreds eV to keV energy range. The balanced fluxes in both directions suggest that the electron beams are bouncing on closed field lines. Although these distribution shapes closely resemble those observed around the geosynchronous orbit and above the auroral zone, whose origins have been attributed to the active auroral acceleration, we report events that are detected in very quiet times (Kp≤1¿), which may cast a new question on the auroral processes during quiet intervals.¿ 1997 American Geophysical Union