To solve such a problem that in which in an opener installed on the edge of a desk or the like, the end of a sealed letter cannot easily be cut regardless of the thickness of the end of the sealed letter with a rotary blade and a receiving roll of the opener, and also the cut end of the sealed letter is scattered downward.

The means for solving the problem is to make a gap between the rotary blade and the receiving roll of the opener adjustable, enable the end of the sealed letter to be cut regardless of the thickness of the end of the sealed letter, and allow one top face of the end of the sealed letter to be cut and opened other than cutting to cut off the end of the sealed letter.