A memory device may include a plurality of memory cells, a peripheral circuit configured to perform a plurality of program loops on selected memory cells among the plurality of memory cells, each of the plurality of program loops including a program pulse application operation and a program verify operation, and control logic configured to control the peripheral circuit to suspend an nth program loop (n is a natural number equal to or greater than 1) among the plurality of program loops in response to a suspend command received during the nth program loop, and to resume the nth program loop with a negative verify operation in response to a resume command. The negative verify operation applies a negative voltage having a voltage less than a state voltage at the time of application of the resume command.