A memory cell formed in a semiconductor substrate, includes a selection gate extending vertically in a trench made in the substrate, and isolated from the substrate by a first layer of gate oxide, a horizontal floating gate extending above the substrate and isolated from the substrate by a second layer of gate oxide, and a horizontal control gate extending above the floating gate. The selection gate covers a lateral face of the floating gate. The floating gate is separated from the selection gate only by the first layer of gate oxide, and separated from a vertical channel region, extending in the substrate along the selection gate, only by the second layer of gate oxide.