Children will be permitted to bring the devices to school but will not be allowed to take them out during school hours, including the meal breaks, The Guardian reported.
The ban was part of the platform for President Emmanuel Macron during his election campaign earlier this year.
Education Minster Jean-Michel Blanquer said the ban would apply to all pupils from the age of six — when they start school — to 15, when they generally start secondary school.
“Sometimes you need a mobile for teaching reasons … for urgent situations, but their use has to be somehow controlled,” Blanquer said during a radio interview.
The ban was also a “public health message to families”, he said, adding: “It’s good that children are not too often, or even at all, in front of a screen before the age of seven.”
The headteachers union's deputy general secretary Philippe Vincent expressed scepticism about the motive behind the ban.
“This new announcement from the ministry leaves us dubious because we’re having trouble understanding what is the real issue here. In general, we’re used to them being logical and pragmatic about things, and here, we can’t find the logic or the pragmatism in the announcements,” he said.
“Are we going to transform a school into a giant locker? I’ve done a little calculation myself: 5300 state schools with an average 500 pupils each, that makes around three million lockers.”