ministry proper; head office; home office
Refers to the central or main office of a government ministry, as opposed to local branches or affiliated agencies.
A directive came from the ministry proper.
He works at the head office, not at a local branch.
this ministry; this department
Used within a government ministry to refer to itself, similar to 'this ministry' or 'our department' in English.
This ministry takes this issue seriously.
I will convey the view of this department.
It was decided that the ministry itself would handle that issue.
Please contact the head office for details.
A notice from the head office arrived at each regional branch.