"Set owb = Workbooks("MyBook.xlsx").
Set owb = Workbooks("MyBook.xlsx"
increments the counter. Set owb = Nothing
is a way to explicity decrement the reference counter. But the same thing happens if the object is declared in a Function or Sub and the Function or Sub terminates*. It's why I don't worry to much about not including a Set WB = Nothing
statement in this kind of subroutine structure. Sub Test()
Dim WB As Workbook
Set WB = ActiveWorkbook
Debug.Print WB.Name
End Sub