Memory device and method of operating the same

The present technology includes memory device and a method of operating the same. The memory device includes a memory block including a plurality of pages, a voltage generator configured to generate a program voltage or a verify voltage applied to a selected page among the plurality of pages, a page buffer connected to the selected page through bit lines and configured to perform a precharge operation, an evaluation operation, and a sensing operation on the bit lines during a verify operation, and a control circuit configured to store page addresses of slow pages of which a program operation speed for each is slower than an average program speed of the plurality of pages, and adjust an evaluation time of the evaluation operation according to the page addresses.