PURPOSE: To hold a container main body under vacuum and to make it possible to easily perform the re-use thereof, by forming a step part to the opening inner peripheral edge of the container main body and engaging a lid plate with the opening of the step part while integrally securing the freely crushable thin plate covering the lid plate to a projected part along with a support plate.

CONSTITUTION: A lid plate 12 is engaged with the step part 11 provided to the opening 11a of the main body 11 of a vacuum container for a seabottom gravimeter to close said main body 11. An L-shaped peripheral circular groove 12a is formed to the outer surface of the lid plate 12 while the outer surface of said lid plate 12 is covered with a thin plate 13 and the outer peripheral edge of said thin plate 13 is integrally fixed to a projected part 11b along with a support plate 14 to hold the interior of the main body 11 to a high vacuum degree. When the main body 11 is opened, a cutter knife 16 is inserted in the peripheral circular groove 12a and revolved therearound one time to easily cut the thin plate 13 so as to separate the central part thereof. As a result, the lid plate 12 is detached and the main body 11 can be opened.