Inspection or observation apparatus and sample inspection or observation method

1. A sample observation method by using a charged particle beam apparatus comprising a charged particle optical column irradiating a charged particle beam, a vacuum chamber, and a sample chamber being capable of storing a sample, the method comprising:

maintaining a pressure of the sample chamber higher than that of the vacuum chamber by a thin film which permits the charged particle beam to be transmitted;

determining a relation between a height of a lower surface of the thin film and a height of a lower end of a lens barrel of an optical microscope;

measuring a distance between the sample and the lens barrel; and

setting a distance between the sample and thin film based on the relation and the distance.

2. The sample observation method according to claim 1 , further comprising moving a sample mount section mounting the sample between a first position where the charged particle beam is irradiated to the sample and a second position where the sample is observed by the optical microscope.

3. The sample observation method according to claim 1 ,

wherein the charged particle beam apparatus comprises a sample mount section mounting the sample, and

wherein the sample mounted on the sample mount section is observed by both of the charged particle beam apparatus and the optical microscope.