Semiconductor device and method of controlling semiconductor device

A semiconductor device comprising:

• a memory cell having a variable resistance device;
• and
• a control unit that controls a voltage applied to the memory cell,
• wherein the variable resistance device includes
• a first electrode containing a first metal material,
• a second electrode containing a second metal material, and
• an insulating film, provided between the first electrode and the second electrode, that contains a third metal material and oxygen,
• the first metal material has a normalized oxide formation energy higher than that of the second metal material, and
• the control unit applies a positive voltage to the second electrode at the time of an operation of increasing a resistance value of the insulating film and an operation of decreasing the resistance value thereof, and applies a positive voltage to the first electrode at the time of an operation of reading out the resistance value of the insulating film.