Non-volatile semiconductor memory device

A non-volatile semiconductor memory device includes a memory array 20, including a plurality of memory elements; a selection part, selecting the memory elements of the memory array based on address data; a mode selection part 30, selecting any one of a RAM mode and a flash mode, where the RAM mode is a mode adapted to overwrite data of the memory element according to writing data, and the flash mode is a mode adapted to overwrite data of the memory element when the writing data is a first value and prohibit overwrite when the writing data is a second value; and a write control part, writing the writing data to the selected memory element according to the RAM mode or the flash mode selected by the mode selection part 30.