A semiconductor device includes a plurality of conductive layers stacked above one another in a first direction and including a first conductive layer, second conductive layers, and third conductive layers, a semiconductor film extending in the first direction through the conductive layers, an insulating film around the semiconductor film between the semiconductor film and the plurality of conductive layers. During a program operation performed on a first memory cell, a program voltage is applied to the first conductive layer while a first voltage is applied to the second conductive layers and a second voltage different from the first voltage is applied to the third conductive layers. The second conductive layers are each connected to gates of second memory cells programmed to store m bits, and the third conductive layers are each connected to gates of third memory cells programmed to store n bits, where n is different from m.