The present invention provides an adapter device adapted for easier
operation of a lid that opens and closes an opening through which a video
camera is to be inserted and on which a viewfinder is to be installed.
The present invention provides an adapter device to which a video camera
device is to be attached, the adapter device including an adapter body
having formed therein a receptacle in which the video camera device is to
be installed and having formed at the rear end thereof an opening through
which the video camera device is to be inserted first at a lens-unit
mount thereof, a lid provided pivotably on a vertical pivot of the
adapter body to open and close the insertion opening, and a mount base
provided on the top of the lid on which a viewfinder is to be installed.