A semiconductor memory device comprises a plurality of memory cells each including a holding circuit for holding memory data, and a read-only output circuit for outputting a signal corresponding to the data held by the holding circuit. The read-only output circuit has a read drive transistor controlled in accordance with a signal held by the holding circuit. A gate length of the read drive transistor is longer than a gate length of a transistor included in the holding circuit. Alternatively, the read-only output circuit has a read access transistor controlled in accordance with a read word select signal, and a gate length of the read access transistor is longer than a gate length of a transistor included in the holding circuit.