we are planning to rent the apartment in paris for 10 days and the owner of it claims that he needs a 300 euros deposit and a copy of my and my fiances passport,is that normal thing to do when renting short term?
to me it sounds kinda fishy ,because where is the guarantee that he is going to give us those 300 euros back and why the heck does he need a passport copy?!

every answer is appreciated!