An easy way to find these things out is to do a dummy booking using

http://matrix.itasoftware.com/

Log in as a guest, search for a sample itinerary (the type you are interested in), set the sales city to 'FRA', click on a flight, click on 'details', click on 'show booking details', and you'll get a breakdown of charges.

This will list all taxes and surcharges (which may be levied by governments, airports or airlines). However, I don't know for Germany, but be aware that a passenger tax/charge, in some countries, can vary according to many factors: whether arriving/departing/transiting, domestic/international, distance of flight, class of service...

Good luck!