A tool for working a substrate has a stator and a working piston, which is intended to move relative to the stator along a working axis and toward the substrate or to hit a fastening element, in order to drive the fastening element into the substrate, also having a drive, which is intended to drive the working piston along the working axis onto the substrate, the drive having a piston coil capacitor and a piston coil arranged on the working piston, the piston coil being electrically connectable to the piston coil capacitor in order during rapid discharge of the piston coil capacitor to have a current flowing through it and to generate a magnetic field which accelerates the working piston relative to the stator.