Recent technological developments require advanced manufacturing technologies for miniaturized and micro-scale components in various types of industrial products, e.g., fuel injection nozzle for automobiles, miniaturized medical tools, microprobes used to measure surface properties, integrated micro-channels used for drug delivery systems, micro-gears, and various aeronautical components. Through-mask electrochemical micromachining (TM-ECMM) is a feasible process for such products. In the present work, the finite elements method (FEM) is used for solving 2-D Laplace equation in the inter electrode gap to determine the potential and flux distribution for the anode shape prediction in TM-ECMM. Algorithm has been developed and implemented in MATLAB to estimate surface erosion of anode for finite time steps. Anode shape and undercut are predicted using FEM and compared with the experimental results. The shape evolution through finite element simulation is approximately complying with the experimental anode profile. This work would later help in tool (cathode) design for TM-ECMM.