Following the cabinet's inaugural meeting, spokeswoman Najat Vallaud-Belkacem said the salary reduction was to "set an example" as the government looks to tackle France's troubled public finances.
The move was also aimed at drawing a distinction between Hollande and former president Nicolas Sarkozy, whose gross salary famously increased by 170 percent to €21,300 ($27,000) per month after he took office in 2007.
The gross salaries of Hollande and Prime Minister Jean-Marc Ayrault will fall to €14,910 per month, while ministers' gross salaries will drop from €14,200 to €9,940 per month.
The head of the main opposition centre-right UMP party, Jean-Francois Cope, denounced the salary cut as a "sham", noting that the new government had 34 members -- 14 more than Sarkozy's first cabinet in 2007.
"Decreasing salaries by 30 percent cannot hide the simple fact that Francois Hollande's government will cost a lot more to the taxpayer," he said in a statement.
However Sarkozy's last government had 31 members including ministers and secretaries of state.
Senior ministers said the government's first concern would be to tackle the European debt crisis and push Hollande's vow to shift the European Union's economic focus from austerity to growth.
"The priority is to disentangle the crisis in Europe," Foreign Minister Laurent Fabius told news channel BFMTV. "I am profoundly European but we need a different Europe, a Europe that is much more focused on jobs."
Finance Minister Pierre Moscovici reiterated that Paris would not ratify the EU's fiscal austerity pact if it does not include measures to boost growth.
"What has been said quite clearly is that the treaty will not be ratified as is and that it must be completed with a chapter on growth, with a growth strategy," Moscovici told BFMTV.
Moscovici also gave assurances that the Socialists would keep public finances under control.
"We must reorient the reconstruction of Europe, but not by turning our backs on budget discipline," he added.
"I want to be very clear, Francois Hollande has said it repeatedly, we must tackle the public debt, reduce deficits, and secure France's situation. That is fundamental, a country that runs up debt is a country that is getting poorer."
Hollande, who defeated right-winger Sarkozy in a May 6th vote, on Wednesday unveiled a government of mainly moderate Socialists and longtime allies.
Vallaud-Belkacem said ministers had also signed a code of conduct against conflicts of interest and that Ayrault had ordered France's Court of Auditors to prepare a report "on the state of our public accounts" by June 1st.
"The mission statement expressed to us was clear: We are here not only to manage the country, but to reform it, to overcome privileges and to improve the lives of the French people," she said.
The new cabinet line-up met Hollande's promise to appoint an equal number of men and women, a first for France, although most of the senior posts went to men.
But it is a cabinet with little experience -- only five of its 34 members have served previously in government and seven are under the age of 40.
The cabinet will help plan the Socialist strategy for the party's campaign to win a parliamentary majority in June legislative elections.
Under France's political system the president requires a parliamentary majority to maintain a government, otherwise the prime minister is in charge of the executive.
Hollande will meanwhile be heading to the United States on Friday for the start of a series of major international meetings, including a gathering of G8 leaders Friday and Saturday at Camp David near Washington, and a NATO summit in Chicago on Sunday and Monday.