Closed container and lid opening/closing system therefor

A closed container comprising:

• a lid having a flat plate-like shape and having an engaged portion provided in said flat plate-like shape;
• a container body having an interior space in which an object can be stored, an opening that allows communication between said interior space and an external space and is to be closed by one side of said flat plate-like shape of said lid, a flange portion that extends from the periphery of said opening parallel to a surface on which the opening is formed and defines a receiving recess in which said lid is received in a state in which said opening is closed by said lid, and an insertion hole that passes from an outer surface of said flange portion to said receiving recess and is provided at a position aligned with said engaged portion in a state in which said lid is received in said receiving recess;
• and
• a latch mechanism having a latch main body that is movable along an axis parallel to said surface on which the opening is formed and extends in the direction of said axis, a link portion that projects from said latch main body in a direction different from the direction along said axis, and an engagement portion disposed at an end of said link portion, wherein
• at least said engagement portion reaches said receiving recess through said insertion hole,
• said engagement portion engages with said engaged portion of said lid disposed in said receiving recess,
• engagement of said engagement portion with said engaged portion and release of engagement thereof are achieved by movement of said latch main body along said axis,
• said engaged portion has an L-shape comprising a first straight portion extending along a direction in which an outer circumferential surface of said flat plate-like shape extends and a second straight portion having an open end on one surface of said flat plate-like shape and extending in the thickness direction of said lid,
• said engagement portion can engage with an inner wall defining the first straight portion of said L-shape, and the engaged state is released by movement of said engagement portion to said second straight portion with movement of said latch main body along said axis, and
• said inner wall is located on the side close to the rear surface of said lid opposed to said opening, the distance between said inner wall and said rear surface being closest at a joining portion of said first straight portion with said second straight portion, and said distance between said inner wall and said rear surface increasing with an increase in the distance from said joining portion.