Mr Macron - brought into politics by Mr Hollande first as a powerful adviser and later as economy minister - will, like his predecessor, make Berlin his first port of call after his inauguration on Sunday.
Nicolas Bay dismissed suggestions Marine Le Pen had suffered a massive defeat to the centrist president-elect on Sunday, as he argued the party was on course to secure more votes.
Macron's big challenge now is to garner support for the crucial legislative election in June. In the Netherlands in March, far-right nationalist Geert Wilders won fewer seats than expected.
Candidates from the two parties that have traditionally dominated French politics for decades, the left-wing Socialists and the Republicans, were knocked out at the first-round stage of the election for the first time since 1958. If he does, he would be able to pick the candidate of his choice to lead the government as prime minister.
Polling suggests that En Marche and another centrist party, Modem, are now the choice of a narrow plurality-26 percent-of French voters, while Le Pen's party, the National Front, comes in at 22 percent.
"Obviously the government elected after June 8th will be sitting down and talking to Monsieur Macron and others about how that system we have works for the benefit of France as well as the benefit of the United Kingdom", she said. But many commentators said the fact that a third of the electorate either abstained or cast blank or spoiled votes on yesterday showed Macron would start his mandate under intense scrutiny.
"After Brexit and Trump's victory, the Western world and Europe have been spared another political quake", said German daily Frankfurter Allgemeine Zeitung, adding that Europe had dodged the "nightmare" of a far-right leader in the Elysee Palace.
On Monday, Macron appeared alongside Socialist President Francois Hollande at World War II commemorations, a cordial meeting of the once close friends who became estranged when Macron launched his presidential bid a year ago.
"Macron, Hollande's former economy minister, started his own independent movement "En Marche" (On The Move") in April a year ago but has no party structure behind him.
The left-wing paper Liberation said he was "under pressure", even before his inauguration which is set to take place next Sunday. A raucous celebration among Macron supporters - which also served as a pep rally for the European Union - gave way to a sombre procession on the Champs-Elysees as the nation remembered its war dead on Victory in Europe day.
Le Pen scored well on France's Mediterranean coast in the south east, getting close to 50 percent in many departments, like the Var, where she gained 49 percent.
Front National vice president Florian Philippot confirmed that the party's name was bound to change as part of this transformation.
Le Pen nevertheless won the support of 10.6 million people.
"While politicians in Europe let out a collective sigh of relief, what the result can't disguise is the level of voter dissatisfaction in France as a whole", said Michael Hewson, economist at CMC Markets.
Leaders in Germany and Britain praised Macron's victory, but viewed it through their own electoral challenges. He had heard and understood the "rage, anxiety and doubt" of the many French electors and would use his five years in office to combat the "forces of division that undermine France".
Rabbi Pinchas Goldschmidt, the president of the Conference of European Rabbis, said in a statement that while Macron's election is "extremely encouraging", his group is "concerned that a third of the French population voted for a risky political leader".