Electrochemical machining (ECM) is a non-conventional process, which enables the modification of a metal’s surface roughness and/or of a work piece’s form. The process exploits the effect of anodic dissolution, allowing the processing of particularly hard metals without causing undesired microstructural changes, such as dislocation formation [1]. In our previous work [2], a homogenized description based on the use of effective parameters is presented. Therein, the processing of the metal is described by a dissolution level which serves as an inner variable. Its evolution is described based on Faraday’s law of electrolysis and depends on an activation function that accounts for the necessary contact with the electrolyte. The inner variable then influences the electrothermally coupled system of equations through the previously mentioned effective description of the used material parameters. Based on a classical rule of mixture, they are calculated by taking into account the properties of the metal and the electrolyte weighted in dependence of the dissolution level. To avoid the used activation function, we now present a new phase-field approach for the electrochemical machining process. The dissolution level serves as a phase-field variable with an evolution described by the Allen-Cahn equation. The formulation is coupled with the electrical system of equations and implemented into a finite element formulation. The presentation is completed by numerical examples, which show the ability of our developed method to model the electrochemical effect of anodic dissolution. [1] Klocke F., Klink A., Veselovac D., Aspinwall D. K., Soo S. L., Schmidt M., Schilp J., Levy G., Kruth J.-P., Turbomachinery component manufacture by application of electrochemical, electro-physical and photonic processes, CIRP Annals, Vol. 63 (2), pp. 703–726, 2014. [2] Van der Velden T., Rommes B., Klink A., Reese S., Waimann J., A novel approach for the efficient modeling of material dissolution in electrochemical machining, International Journal of Solids and Structures, Vol. 229, pp. 111106, 2021.