The exchange rate at banks and exchange offices differs slightly. Currency exchange offices are located throughout Baku and other large cities. Majority of hotels, shopping malls and large supermarkets accept credit cards. In the small shops and restaurants, though, one will have to pay cash.
If you run low on cash, you needn`t worry as ATMs are available everywhere in  the capital of Azerbaijan and many of them work 24/7. At ATMs you can withdraw Manat or USD.