How long you going for?
Do the same company employ you here ie is this a secondment?
What nationality are you?
Basically if you are going to take up a new job in germany, the irish revenue don't care about you, you will be subject to german tax only, this could change depending on your answers to the questions above.
You might like to check out your social welfare benefits etc. I believe as we are all EEC members there is a tie-in between your Irish and your German contributions. Probably not important to you at this point in time, but I would suggest that when you are leaving Germany you take home with you a record of any social welfare contributions you have made.
Thank you. To answer Glenbhoy, I am Irish and I will be changing to a German company for 6 months. As far as I am aware or at least what I am told is that I am still eligible under Irish tax rules, however, I will pay German ones while I am there and then I can claim the difference when I return to Ireland? This is the scenario when you travel to the U.S. Should I expect it to be the same when I travel to another E.U. state?