Currency Exchange at Frankfurt Airport

Every time I have arrived in Frankfurt (6 times if I remember), I have found a bank ATM at the exit from the concourse into the main hall. In every case, the discount rate has been whatever my bank takes, i.e., no fee from the ATM. Don't exchange money; exchange desks take a much larger fee than ATMs. Get it from your account at the ATM.

As soon as you leave the secured area at the airport, you will find ATM machines spaced about every 50 meters, which roughly corresponds to each exit. If you can use an ATM in the US, you can use an ATM in Europe.

Use the Deutsche Bank ATM's. They are everywhere.

Do not use the Money Exchanges unless you really want to pay 20 cents more per euro. May not sound like a lot, but for a 100 euro, do you want to pay 20$ more than if you got your 100 from an ATM? I wouldn't.
They have a few ATM's scattered around the airport too, so don't use those, only use the Deutsche Bank ones.

Just make certain that it is bank owned and operated ATM, there will be no fee. If it is a private ATM it will charge fees.
Never go to a money exchange, either they will charge a huge fee, or if they say "no fees" then they will get their money by an exchange rate that will cost you 5-10% -see their posting of "buy" and "sell" -the actual interbank rate that a system ATM will give you will be in the middle of those two numbers. The only exception is to cash in small amounts of leftover currency when leaving a country you are not likely to be back to.

Make sure that you notify your bank that you will be using your ATM card in Europe (give them countries and dates). Banks routinely deny transactions if they seem unusual, and someone making a withdrawal from a foreign country on your account is probably unusual. Credit card companies, too.