Memory device and method of operating the same

A memory device comprising:

• a plurality of memory cells;
• a peripheral circuit configured to perform a program operation on the plurality of memory cells and perform program verify operations each including at least one verify loop corresponding to a plurality of program states programmed in the program operation;
• and
• a control logic configured to control the peripheral circuit to perform a verify pulse apply operation and an additional verify pulse apply operation when a target verify loop count, which is a number of verify loops performed in the program verify operation corresponding to a target program state among the plurality of program states, exceeds a reference count corresponding to the target program state, and determine whether the program verify operation corresponding to the target program state is failed based on results of the verify pulse apply operation and the additional verify pulse apply operation,
• wherein a verify voltage higher than a verify voltage of the verify pulse apply operation is applied to the memory cells in the additional verify pulse apply operation.