A lock for locking a sterilization container has box-like bottom part and a container cover that can be removed and placed airtightly and connected on the bottom part by a seal to form a closed sterilization space. The lock has a tensioning lever pivotable into an opened position, and a closing flap rotatable about an axis of rotation, with a positive-locking closed position with the tensioning lever. The tensioning lever is able to be brought via the closing flap, during the rotary motion of the closing flap into an opened rotated position, with the closing flap disengaged from the tensioning lever after a further rotary motion into a fully opened end position. The tensioning lever may be fixed in open, and the closing flap positive-lockingly engages with the tensioning lever during closing and the tensioning lever is able be to moved into a closed tensioned position by the closing flap.