Herein, a mesoporous silicon film (5 μm thick, diameter of pores ranging from 60 to 70 nm) was prepared through an electrochemical etching of a silicon wafer, and its performance for lithium-ion microbatteries was investigated. A sluggish penetration of the electrolyte into the pores of the material along its depth was clearly observed thanks to cyclic voltammetry measurements, as in fact, the lithiation and delithiation peaks raise during scanning. The penetration of the electrolyte in the mesoporous layer was monitored by elemental analysis and by energy-dispersive X-ray spectroscopy coupled with scanning electron microscopy. Herein, it is clearly reported that after 50 voltammetric cycles, electrochemical reactions take place in the whole depth of the porous silicon layer. In contrast, after only 10 cycles, the bottom part of the silicon pores seems to not be affected. Galvanostatic cycling at a rate of 300 μA cm− 2 was performed for two different lower cut-off voltages. A charge limitation of 0.1 V resulted in a stable specific capacity of 1910 mAh g− 1. For a deeper charge with a potential limitation of 0.07 V, a higher specific capacity of 2480 mAh g− 1 was reached but, unfortunately, this was accompanied by a severe fading of the performances. This phenomenon was attributed to the strong mechanical damages in the porous structure of the silicon negative electrode.