Abstract: We present a demonstration of a three grating Talbot-Lau interferometer for electrons. As a proof of principle, the interferometer is used to measure magnetic fields. The device is similar to the classical Moiré deflectometer. The possibility to extend this work to build a scaled-up electron deflectometer or interferometer for sensitive magnetic field sensing is discussed. (Version 1 description: Image data of electron diffraction and electron counts as a function of applied magnetic field) The electron double-slit data are found at SANDY Record ID 62.