How long will the German visa be issued?

Visa processing takes 15 days to about one month.

According to German law, consulates only have the right to issue entry visas. Once the residence permit for staying in Germany for more than three months is involved, it must be approved by the local foreigners' administration before an entry visa can be issued. That's why the embassy has to send everyone's materials to Germany, and it takes about 15 days to a month to wait for the visa.