There isn't one.
There is no sovereignty on Antarctica. This means that there is no national Antarctic flag, currency or stamps, because there is no government to issue them. Any 'Antarctic flag' is a souvenir sold to you by a profiteer.
All research stations fly the flags of the countries that support the station. There is no sovereignty on the continent and there is no official Antarctic flag. As well, there are no Antarctic stamps, or currency. Claiming nation-states do issue commemorative stamps and include Antarctic images on their currency, as ways to maintain their territorial claims.
Because there's essentially no place to use currency on the continent -- no commercial enterprises, and because there is no sovereignty on the continent, there is no 'Antarctic currency'. People may purchase items, however, that are for sale and the currency used is the currency of the transaction.
Antarctica is a continent with no countries. There is no Antarctic flag, or currency or stamps or cities or states.
Since there is no commerce on Antarctica, there is no need for currency. As well, since Antarctica is not sovereign, there is no Antarctic currency. Any cash transactions usually occur in the currency of the research station where the transaction takes place.
Antarctica does not have a flag. There are no nation-states on the continent, so, as well, there is no Antarctic currency, Antarctic stamps and so forth. Any mementos purported to be 'Antarctic' in this vein are souvenirs sold by profiteers.
¤ is the universal currency symbol. When used, it means currency.
The currency used is Euro
There is no Antarctic currency. There is no government on the continent, so no money is minted, nor stamps, nor flags.
Because there is no sovereignty on the Antarctic continent, there is no official currency -- or stamps, or flags. Any such object is a tourist souvenir and not officially representing anything except some cleaver commerce.
You are Douglas Mawson.
The currency used in Germany is the euro (€).