First of all, Maestro is not a credit card, but belongs to Debitkarte of MasterCard. This kind of EC/Maestro debit card is very common in Germany. It connects to your Girokonto. If there is no money in Konto, you can't swipe your card.

In addition, if your classmate's debit card belongs to Deutsche Bank, you should only withdraw money at the domestic DB counter. In addition to real-time exchange rate conversion, there are some charges for specific tariffs. Consult the bank specifically.

You can also withdraw cash from China Bank or China Merchants Bank. Consult the bank specifically. However, it is not recommended to withdraw cash. Because the low exchange rate does not count, there are intermediate costs.