passport stamp
 

sir i have been travel in schengen States when i exit immigration departure they did not stump my passport. so by this reason may can face the problem in airport anytime visa applying time in any embassy

Chances are, your passport was scanned when you left the Schengen area and the exit has been recorded. Keep your boarding card as proof that you left in case anyone asks, but chances are - nobody will ever ask.

Keep records of your exit from Schengen in case anyone asks. I'm pretty certain your exit was recorded electronically.

No stamps are necessary. All of Schengen uses the same border crossing system now. Unless you exited at a border where they did not scan your passport of course. But exit stamps aren't really needed. You will have entered another country on exit anyway.