"My first impression from the proposals presented... is that the Commission's total volume of the budgetary framework is, for the German government, irresponsibly high," Foreign Minister Guido Westerwelle said in a statement.
"In times of general budgetary consolidation Brussels must also send a message to frugally and sustainably economise."
He said the European Union, like debt-wracked members of the eurozone, needed to sharply limit spending.
Westerwelle said Germany saw one percent of EU economic output - forecast as €1 trillion ($1.4 billion) for the 2014-2020 period - as sufficient to cover EU spending during that time.
He also blasted the Commission's calls for the introduction of an EU sales tax and financial services tax, saying a majority of EU states opposed such a move.
"We don't need such taxes because the EU does not have a financing problem," the minister, a member of the pro-business Free Democrats, said.
He said he welcomed new provisions for research, education and innovation and called on the EU to invest an even greater share of its budget in these areas by shifting funds from other, unspecified expenditures.
The European Commission urged the introduction of an EU sales tax and financial services tax as part of an overhaul of the next EU budget.
The proposals from Commission president Jose Manuel Barroso to seek new sources of revenue aim to allow the bloc's executive arm to raise its own funds rather than depend so heavily on funding from the EU member states.
The outline of the next seven-year budget totalled €1.025 trillion in commitments or about 1.05 percent of output. Britain also slammed the proposals as "unrealistic".
Germany, the biggest economic power in the EU, is the top contributor to the the 27-member bloc's budget with payments of €20 billion per year. Subtracting what it receives from the EU budget, its net annual contribution is €8 billion.