French Europe Minister Harlem Desir called the move "scandalous" and said it raised questions about the EU's conflict of interest rules.
Ex-commissioners are free to take up a new role 18 months after leaving.
Despite accepting the job after 20 months, Mr Barroso has come under fire for ignoring the spirit of the rules.
Mr Desir drew attention to the ill-timing of the job with Goldman Sachs.
"It's a mistake on the part of Mr Barroso and the worst disservice that a former Commission president could do to the European project at a moment in history when it needs to be supported and strengthened," he told the French parliament, referring to Europe's shock after Britain voted to leave the EU on 23 June.
The bank hired Mr Barroso as an adviser and non-executive chairman of its international business, with a brief of advising the bank on the consequences of Brexit.
Mr Barroso has said he hopes to bring his EU experience to bear as the bank's London operation deals with Britain's imminent negotiation of withdrawal from the EU.
In his new role, Mr Barroso will be able to draw on his intimate knowledge of the EU and have access to many officials and politicians he worked with at the European Commission.
Mr Desir's attack in the French parliament was the latest in a sustained tirade against Mr Barroso's appointment, with some calling it "shameful".
French Finance Minister Michel Sapin told reporters on Tuesday "If you have loved Europe, you shouldn't do this to it, especially not now," adding: "But this doesn't surprise me from Mr Barroso."
The European Ombudsman has called for the EU to tighten rules on commissioners taking appointments after leaving office.
Ombudsman Emily O'Reilly said adhering to technical rules did not absolve former staff of a wider duty to show integrity.
"Any suggestion that the spirit of the law is being ignored risks undermining public trust in the EU," he said.

That's why so many Labour MPs feared a miscalculation when their party's leader brought his old comrade back into the fold.
But his staggering comments today about Hitler and anti-Semitism crossed a line - they were enough for Jeremy Corbyn to suspend him.
But the problem for the leader doesn't end with that act.
No one believes that Jeremy Corbyn himself tolerates discrimination against Jews.
But on repeated occasions Labour has been slow and clumsy in closing down cases of anti-Semitism among its members when they emerge.
Any moments of delay or doubts about the leadership's determination, open the window a tiny crack to the kind of intolerance that the vast majority of the Labour Party, and indeed the public, find appalling.
Public denials that there is even a issue could make it even worse. Perhaps in politics as in normal life, the first step towards fixing a problem is acknowledging that it exists.
And with only a week before Jeremy Corbyn's first big test at the polls, In elections in London, Scotland, Wales, and al round England, it's the kind of mess, and political distraction Labour could do without.

A southbound Volkswagen Crafter Van collided with a Peugeot Partner Van on the A702, just north of Candymill Road, near Biggar, at 17:35 on Thursday.
A 58-year-old male passenger in the Peugeot is in a serious but stable condition in hospital.
The 32-year-old driver was uninjured as was the 26-year-old male driver of the Volkswagen van.
Police said both vehicles suffered extensive damage in the collision and the road was closed for several hours while officers investigated the scene.
France has called on the former head of the European Commission, Jose Manuel Barroso, not to take up a job advising US bank Goldman Sachs on Brexit.
[NEXT_CONCEPT]
For years it has been more surprising when Ken Livingstone hasn't raised hackles than when he has.
[NEXT_CONCEPT]
Police have appealed for witnesses to a crash between two vans which closed a Lanarkshire road for several hours.