Macron, visiting Burkina Faso at the start of his first African tour, said the money could be used to help firms maximise value from agriculture, but also the digital sector.
The money will be provided by the France's Public Investment Bank, which offers firms tailored funding, and the French Development Agency.
Macron said the ultimate objective is "to multiply this fund tenfold, which is absolutely do-able if we appeal to our European allies or other private financiers, European or non-European."
With Africa facing a population explosion over coming decades, the continent is hoping to create 450 million jobs by 2050 and Macron said such investment "is a necessity in order to face up the demographic challenge."
"Our collective responsibility is to enable Africa to succeed as our fates are linked. If Africa fails we all lose together as Europe will be overwhelmed by a wave of migration... and deep imbalances" of prosperity, Macron said.