A semiconductor memory device includes a row control circuit block and a column control circuit block each performing an access control over a memory cell array, a data I/O circuit block transmitting and receiving data to and from the memory cell array, and a control circuit changing at least a part of the row control circuit block, the column control circuit block, and the data I/O circuit block from a standby state into an active state in response to a setting of a predetermined mode signal to a mode register. According to the present invention, even if it is necessary to turn predetermined circuit blocks into the active state by an operation other than a read or write operation, there is no need to always set these circuit blocks into the active state.