A memory device of an embodiment includes a memory cell array and a controller. In the memory cell, data is written per page unit and is erased per block which is a multiple the page unit of a natural number of two or more. The block includes memory strings, each including memory cells capable of storing data of one or more bits with a threshold voltage indicative of an erase state in which data is erased and one or more threshold voltages which are higher than the voltage indicative of the erase state and indicate written states in which data is written. The controller selects one of adjustment values of positive and negative values based on data read from a first memory cell of the memory cells, and reads data from a second memory cell of the memory cells using the selected adjustment value and a first read voltage.