A peep preventing device (100, 100', 200, 200') comprising: a transparent substrate (110, 210); a plurality of first electrodes (120, 220) on the transparent substrate (110, 210); a transparent insulating body (130, 230) on the transparent substrate (110, 210), wherein the insulating body (130, 230) has a plurality of recesses (131, 131', 231, 231') in one-to-one correspondence with the first electrodes (120, 220), each of the recesses (131, 131', 231, 231') has an opening facing towards the transparent substrate (110, 210), the first electrodes (120, 220) are located in the recesses (131, 131', 231, 231'), respectively, and an area of a section, taken along a plane parallel to the transparent substrate (110, 210), of each of the recesses (131, 131', 231, 231') gradually reduces in a direction away from the transparent substrate (110, 210), in particular the section has an elliptical shape or a polygonal shape; a plurality of transparent second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') each of which comprises a second electrode sidewall portion (141, 141a, 141b, 241, 241a, 241b) covering a sidewall (131a, 131a', 231a') of one of the recesses (131, 131', 231, 231'), wherein closed spaces (150, 150', 250, 250') are defined between the insulating body (130, 230) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') and the transparent substrate (110, 210), electrophoretic liquids (151, 251) are contained in the closed spaces (150, 150', 250, 250'), respectively, and the electrophoretic liquids (151, 251) contain reflective charged particles (152, 252) adapted to adhere to the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') when a first electric field is applied between the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240'); and a switching device (170, 270) electrically connected with the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240'), and the switching device (170, 270) is configured such that, when the switching device (170, 270) is in a first operating state, the first electric field is applied between the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') so that the reflective charged particles (152, 252) adhere to the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240'); and when the switching device is in a second operating state, a second electric field opposite in direction to the first electric field is applied between the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') so that the reflective charged particles (152, 252) adhere to the first electrodes (120, 220). a transparent substrate (110, 210); a plurality of first electrodes (120, 220) on the transparent substrate (110, 210); a transparent insulating body (130, 230) on the transparent substrate (110, 210), wherein the insulating body (130, 230) has a plurality of recesses (131, 131', 231, 231') in one-to-one correspondence with the first electrodes (120, 220), each of the recesses (131, 131', 231, 231') has an opening facing towards the transparent substrate (110, 210), the first electrodes (120, 220) are located in the recesses (131, 131', 231, 231'), respectively, and an area of a section, taken along a plane parallel to the transparent substrate (110, 210), of each of the recesses (131, 131', 231, 231') gradually reduces in a direction away from the transparent substrate (110, 210), in particular the section has an elliptical shape or a polygonal shape; a plurality of transparent second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') each of which comprises a second electrode sidewall portion (141, 141a, 141b, 241, 241a, 241b) covering a sidewall (131a, 131a', 231a') of one of the recesses (131, 131', 231, 231'), wherein closed spaces (150, 150', 250, 250') are defined between the insulating body (130, 230) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') and the transparent substrate (110, 210), electrophoretic liquids (151, 251) are contained in the closed spaces (150, 150', 250, 250'), respectively, and the electrophoretic liquids (151, 251) contain reflective charged particles (152, 252) adapted to adhere to the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') when a first electric field is applied between the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240'); and a switching device (170, 270) electrically connected with the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240'), and the switching device (170, 270) is configured such that, when the switching device (170, 270) is in a first operating state, the first electric field is applied between the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') so that the reflective charged particles (152, 252) adhere to the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240'); and when the switching device is in a second operating state, a second electric field opposite in direction to the first electric field is applied between the first electrodes (120, 220) and the second electrodes (140, 140a, 140b, 140', 240, 240a, 240b, 240') so that the reflective charged particles (152, 252) adhere to the first electrodes (120, 220).