Semiconductor memory device and method of operating the same

A method of operating a semiconductor memory device, the method comprising:

• electrically connecting local word lines of the memory block to global word lines;
• applying an operation voltage to the global word lines and transmitting the operation voltage to the local word lines;
• controlling the local word lines to be in a floating state by electrically blocking the global word lines from the local word lines;
• and
• discharging the global word lines after the local word lines are controlled to be in the floating state.

A method of operating a semiconductor memory device, the method comprising:

• electrically connecting local word lines connected to a memory block to global word lines;
• applying a read voltage to a selected local word line among the local word lines through a selected global word line among the global word lines, and applying a pass voltage to unselected local word lines through unselected global word lines among the global word lines;
• floating the local word lines by disconnecting the local word lines from the global word lines;
• and
• discharging the global word lines.