According to one embodiment, a holder includes a top member, a side member, and a bottom member. The top member has a hole for allowing transmission of a charged particle beam, and the sample is mountable in the hole. The bottom member is provided to overlap with the top member in a plan view. The side member is connected to a part of the top member and a part of the bottom member such that the top member and the bottom member are separated from each other in a cross-sectional view. An opening portion is a region surrounded by the top member, the side member, and the bottom member, and a scintillator is provided in the opening portion.