A word line activation circuit having a temporary memory circuit for storing word line inactivation information for inactivating a word line of a defective memory cell, and an inactivation address sensing circuit for determining whether or not a redundant memory cell is to be used in accordance with the word line inactivation information and an address specification signal is provided for each of word lines. When the inactivation address sensing circuit determines that the redundant memory cell is to be used, a redundant word line is activated by a redundant word line activation circuit.