A non-volatile semiconductor storage device includes an memory cell array including first and second blocks, each of which includes a plurality of memory strings each having n (n: natural number) memory cells, and a optionally a peripheral circuit for controlling the memory cell array. In this non-volatile semiconductor storage device, n signal lines are arranged in the first block, and m (n>m, m: natural number) signal lines are arranged in the second block, such that the second block size is smaller than the first block size.