Because a sample holder 100 is composed of a plurality of convex parts 1 provided on a top face of a base substance 2, and the plurality of convex parts 1 are spherical surfaces 1a formed of a single crystal or amorphous material, frictional wear of the sample at contact parts between a sample 4 and the convex parts 1 is reduced, thereby making it possible to inhibit particle generation. Further, because a joining layer 3 is formed of a single crystal or amorphous material, there is no defect that particles scattered on the sample holder 100 fill up it, which makes it possible to easily keep it in a clean state by cleaning, and it is possible to effectively reduce reattachment of particles to the sample 4.