Nonvolatile semiconductor memory device and method of manufacturing the same

A nonvolatile semiconductor memory device, comprising:

• a plurality of first lines;
• a plurality of second lines crossing said plurality of first lines;
• a plurality of memory cells each connected at an intersection of said first and second lines between both lines and including a variable resistor operative to store information in accordance with a variation in resistance;
• a protection film being a multi-layered film covering a side surface of said variable resistor;
• and
• an interlayer-insulator film being buried between said memory cells arranged in a direction of extension of said first lines via said protection film,
• wherein said protection film directly contacts an entire planar surface, said planar surface comprising a first side surface of said variable resistor of a first memory cell of said memory cells;
• a second side surface of said variable resistor of a second memory cell of said memory cells, said second memory cell being adjacent to said first memory cell in said direction;
• and a third side surface of said interlayer-insulator film, and said first, second, and third side surfaces being on the same side in a direction of extension of said second lines.