1. A sample inspection apparatus comprising: a charged particle source; a charged particle beam optical system which irradiates a sample with a charged particle beam emitted from the charged particle source; a detector which detects secondary electrons emitted from the sample; and probes which are brought into contact with the sample, and from which signals are obtained to form an image; wherein: a sample image is formed based on a current flowing through the probes or a voltage generated between the probes due to irradiation with the charged particle beam; the sample image is obtained at each of a plurality of different sample temperatures; and a new image is formed by addition or subtraction of signals of the plurality of sample images.