  The quest for the value of the electron's atomic mass has been subject of
continuing efforts over the last decades. Among the seemingly fundamental
constants which parameterize the Standard Model (SM) of physics and which are
thus responsible for its predictive power, the electron mass me plays a
prominent role, as it is responsible for the structure and properties of atoms
and molecules. This manifests in the close link with other fundamental
constants, such as the Rydberg constant and the fine-structure constant
{\alpha}. However, the low mass of the electron considerably complicates its
precise determination. In this work we present a substantial improvement by
combining a very accurate measurement of the magnetic moment of a single
electron bound to a carbon nucleus with a state-of-the-art calculation in the
framework of bound-state Quantum Electrodynamics. The achieved precision of the
atomic mass of the electron surpasses the current CODATA value by a factor of
13. Accordingly, the result presented in this letter lays the foundation for
future fundamental physics experiments and precision tests of the SM.
