A method of verifying a non-volatile memory device includes precharging a bit line to a high level through a sensing node by applying a first voltage to a bit line select transistor coupled between the bit line and the sensing node; applying a verifying voltage to a plurality of word lines; disconnecting the bit line from the sensing node; and coupling the bit line to the sensing node by applying a second voltage to the bit line select transistor so as to detect a level of the bit line, the second voltage being smaller than the first voltage, wherein, a difference between the first voltage and the second voltage in a verifying operation is higher than a difference between a first voltage and a second voltage that are used in a read operation.