File menu > Exit
Exit closes the program. If you have unsaved work, you'll be asked if you want to save it.
Procedure
To exit the program:
Choose File > Exit.
Click the Yes, No, or Cancel button.
If you click Yes the scene is saved, if you click No the scene is not saved, if you click Cancel the Exit operation is canceled.
Note: You can also click the Close button (the X) in the upper-right corner of the application window to exit.