Provided is memory which is capable of dynamically changing memory cell bit reliability and of switching the operating mode so as to accommodate process variations, thereby reducing the operating voltage. The memory is provided with a mode control line selection circuit for dividing mode control lines in to word units and using control line selection signals and global control signals to control the mode control lines divided into word units, and a word line selection circuit for dividing the word lines that control the conduction of switching unit into word units and using word line selection signals and global word signals to control the word lines divided into word units. The mode control line switching circuit is used to switch between a 1 bit/1 cell mode and a 1 bit/n cell mode in word units.