US President Donald Trump's top trade adviser, Peter Navarro, this month said Germany was exploiting the exchange rate for trade purposes. German Chancellor Angela Merkel was among those who said the comments were off the mark.
"These attacks clearly make no sense for a number of reasons," Sapin told the Handelsblatt newspaper. He said the euro moved freely and the ECB made its monetary policy decisions independent of member countries.
"The ECB never tries to manipulate the exchange rate of the euro to achieve trade or competitive policy goals," he said.
"The euro is the currency of the entire euro zone. On the international level what counts is the surplus of the entire eurozone, not that of Germany."
Sapin said he hoped that Trump would understand quickly how advantageous and important ties with the European Union were for the well-being of the United States.
He said EU officials were still trying to lift growth in the bloc and push for structural reforms in some states, but it also important for countries like Germany to increase investments.
"Germany could be more ambitious in this area," Sapin told the newspaper. Europe still needed to restore investments to levels seen before the global financial crisis, he said.
"If we all only pull in one direction, namely reducing budget deficits, the adjustments (in Europe) will be even harder," he said.