The present invention is a modular partition system obtained by assembling removable elements. The system includes at least one mast and at least one panel made integral with each other. The panel includes a frame, on at least one face of which is stretched a canvas. The frame includes a retainer to this end of stretching, on its perimeter and longitudinally. The canvas includes, on the perimeter of its rear face, a hooking device aimed at cooperating with the retainer. The mast includes a profile, or an assembly of profiles, each profile having a device designed capable of permitting directly or indirectly fastening the panel. The present invention is essentially characterized in that the mast includes a device for retaining a mast canvas, at least a portion of which is aimed at covering at least the portion of the mast that is visible.