Patent ID: 7783213

Claim:
An insulation resistance measuring method comprising: charging a surface of a sample to give an electric field intensity in a thickness direction of the sample; scanning the charged surface of the sample in a two-dimensional manner by irradiating a charged particle beam to the sample; obtaining a detection signal generated by the scanning; and measuring a dielectric intensity of the sample based on the detection signal obtained, wherein the sample is a latent-image support object, and a dielectric intensity of the latent-image support object is measured by the measuring, and wherein the latent-image support object has a percentage of an insulation resistance region which is 99% or more when the electric field intensity given in the thickness direction of the latent-image support object is above 30 V/micrometer and below 40 V/micrometer and an amount of electric charge irradiated to the latent-image support object is above 1 E-8 coulomb/mm 2 .