An evaluation method for insulation performance includes: a step α of applying a DC voltage to a first insulator and measuring an integration value of a current flowing through the first insulator from a start of application of the DC voltage after a prescribed time period; a step β of applying a DC voltage to the second insulator on an applying condition that is identical to that in the step α and measuring an integration value of a current flowing through the second insulator from a start of application of the DC voltage after a prescribed time period; and a step γ of comparing (i) a first graph obtained in the step α and (ii) a second graph obtained in the step β, to evaluate a difference between insulation performances of the insulators.