“We will install surveillance cameras on our satellites so we will know who is approaching us,” Defence Minister Florence Parly said on French TV station CNews.
French last year detected attempts by Russia to intercept transmissions from a military satellite used by the armies of France and Italy for secure communications, Parly said on Friday.
The French investment plan comes weeks after US President Donald Trump announced a plan to create a “Space Force”, a new branch of the U.S. military by 2020.
Parly also said the French government was evaluating the construction of one or two aircraft carriers to replace its existing one.
Earlier this month, it emerged that a Russian satellite attempted last year to spy on a satellite providing secure communications for the French military.
The Athena-Fidus satellite, operated jointly with Italy, was approached "a bit too closely" by Russia's Luch-Olymp craft, known for its advanced listening capabilities, Parly said.
"It got so close that we might have imagined it was trying to intercept our communications," she said at France's National Centre for Space Studies (CNES) in Toulouse, southern France.
"Trying to listen to your neighbours is not only unfriendly. It's an act of espionage."