This paper describes the new write/erase operation methods in order to improve the read disturb characteristics for Flash EEPROM cells which are written by channel hot electron injection and erased by F-N tunneling emission from the floating gate to the substrate. The new operation methods is either applying a reverse polarity pulse after each erase pulse or applying a series of shorter erase pulses instead of a long single erase pulse. It is confirmed that by using the above operation methods, the leakage current can be suppressed, and then the read disturb life time after 105 cycles write/erase operation is more than 10 times longer in comparison with the conventional method. This memory cell by using the proposed write/erase operation method has superior potential for application to 256 Mbit Flash memories as beyond.