A memory includes bit lines, word lines, and memory cells connected between first and second BLs. The cells arranged in an extending direction of the BLs constitute columns. The second BL is shared between two columns. The cells in a first pair of columns are arranged to be shifted in the extending direction of the BLs by a half-pitch from the cells in a second pair of columns. The device includes a dummy cell having an equal distance from the adjacent memory elements. Further, the device includes a row decoder driving the cells in the first pair of columns by driving paired word lines, and driving the cells in the second pair of columns by driving paired word lines. Each cell includes selection transistors. The selection transistors are connected in parallel between the memory element and the first BL. Gates of the transistors are connected to different WLs.