1. A variable resistance nonvolatile memory element forming method of performing a forming for a variable resistance nonvolatile memory element, the forming being initialization to change the variable resistance nonvolatile memory element from a first state to a second state, the first state being a state after manufacturing the variable resistance nonvolatile memory element, and the second state being a state reversibly changeable between a high resistance state and a low resistance state depending on a polarity of an applied voltage pulse, wherein the variable resistance nonvolatile memory element has a resistance value that is higher in the first state than in the high resistance state, said method comprising: determining whether or not the resistance value of the variable resistance nonvolatile memory element is lower than the resistance value in the high resistance state; and applying a voltage pulse of a voltage to the variable resistance nonvolatile memory element, when said determination is made that the resistance value of the variable resistance nonvolatile memory element is not lower than the resistance value in the high resistance state, the voltage having an absolute value not exceeding an absolute value of an absolute value maximum voltage that is a sum of a forming start voltage and a predetermined voltage, and the forming start voltage having a minimum absolute value and being required to change the variable resistance nonvolatile memory element from the first state to the second state.