Application.Quit
But if you have unsaved documents then you will be prompted.
To avoid it and close workbooks without saving:
'------CODE START-----
Dim wrkBook As Workbook
For Each wrkBook In Workbooks
wrkBook.Saved = True
Next
Application.Quit
'------CODE END-----
or save all workbooks
'------CODE START-----
Dim wrkBook As Workbook
For Each wrkBook In Workbooks
wrkBook.Save
Next
Application.Quit
'------CODE END-----
regards