A semiconductor memory device includes memory blocks, a main word decoder to set a main word line to a first potential for activation, a second potential, or a third potential, a circuit to generate a cyclic signal that indicates timing at intervals, a block selecting circuit to select a memory block to be accessed, a successive-selection circuit to select the memory blocks one after another, and a circuit configured to control the main word decoder such that unselected ones of the main word lines of a memory block selected by the block selecting circuit are set to the third potential, such that the main word lines of the selected memory block are maintained at the third potential after access, and such that the main word lines of a memory block selected by the successive-selection circuit are set to the second potential at the timing indicated by the cyclic signal.