A semiconductor memory according to an example of the present invention comprises first and second bit lines having a twisted bit-line architecture in which the first and second bit lines are alternately twisted at a constant period in first and second columns, a first cell block which is disposed in the first column, a first block select transistor which is connected between the first or second bit line and one end of the first cell block, a second cell block which is disposed in the second column, and a second block select transistor which is connected between the second or first bit line and one end of the second cell block.