Police said about 60 shots were fired at the high-security residence on a busy street of a northern suburb. At least four bullets were lodged in the walls of the house and four hit the metal gate of its perimeter. No one was hurt.
Anti-German sentiment has grown during Greece's prolonged economic crisis and many of those struggling with record unemployment and falling living standards blame Germany's insistence on fiscal rigour for their economic woes.
Germany is the biggest single contributing nation to Greece's €240 billion bailout that have kept the country afloat since 2010 and saved it from bankruptcy. Germany has at least €15bn of bilateral loans extended to Greece as part of the bailout.
No one has claimed responsibility for the attack, which police believe was carried out by members of leftist guerrilla groups. A police official, who spoke on condition of anonymity, said at least two assailants on foot were involved.
"Whoever is responsible for this act: You will not succeed in disrupting the close and friendly relations of our two countries," said German Ambassador Wolfgang Dold, who was at home at the time of the incident.
The residence was also the target of an attack in 1999.