The container (1) is formed with an internal space in which insects can be accommodated, an opening (11) is formed through the internal space and the outside, and other than the opening (11) is closed so that insects cannot pass through. ing. The pair of rails (2) are provided in parallel to each other on the outer surface of the container (1) on both sides of the opening (11) across the opening (11), and the opening (11) of the container (1) is formed. The gap between the surface and the cover (3) is maintained at such a size that insects cannot pass through, and the cover (3) is slidably held outside the container (1). The sample holder holds the sample and is slidably held on the rail (2). When the sample is held on the rail (2) so as to be slidable, the sample is held inside the opening (11). Exposed to space. The sample holder holding the sample and the cover (3) are slid between the pair of rails (2) in a state where one side is in contact with each other, and the position and the opening (11) where the cover (3) covers the opening (11) 11) can be moved between the positions covered by the sample.収容体（１）は、虫を収容しうる内部空間が形成され、内部空間と外とを通じる開口（１１）が形成されて、開口（１１）以外は虫が通過するのを不能に閉じられている。一対のレール（２）は、開口（１１）を挟んで開口（１１）の両側で収容体（１）の外面に互いに平行に設けられ、収容体（１）の開口（１１）が形成された面とカバー（３）との隙間を虫が通過できない大きさに維持して、カバー（３）を収容体（１）の外側で摺動可能に保持する。試料ホルダは、試料を保持してレール（２）に摺動可能に保持され、試料を保持した状態でレール（２）に摺動可能に保持されたときに、試料を開口（１１）から内部空間に露出する。試料を保持した試料ホルダとカバー（３）を、一辺を互いに接した状態で、一対のレール（２）の間で摺動させて、開口（１１）をカバー（３）が覆う位置と開口（１１）を試料が覆う位置との間で移動できる。
