A dynamic RAM incorporates a plurality of dynamic memory cells, each of which comprises a MOSFET having a gate set as a select terminal, one source and drain set as input/output terminals, and the other source and drain connected to storage nodes of a capacitor, a plurality of word lines respectively connected to the select terminals of the plurality of dynamic memory cells, a plurality of complementary bit line pairs respectively connected to the input/output terminals of the plurality of dynamic memory cells, and a sense amplifier array comprising a plurality of latch circuits which respectively amplify differences in voltage between the complementary bit line pairs placed so as to extend in directions opposite to each other from each pair of input/output terminals. Power supply lines are provided in mesh form inclusive of a portion above word drivers.