[摘要]:We determined the experimental value of the g factor of the electron bound in hydrogenlike (28)Si(13+) by using a single ion confined in a cylindrical Penning trap. From the ratio of the ion's cyclotron frequency and the induced spin flip frequency, we obtain g = 1.995 348 958 7(5)(3)(8). It is in excellent agreement with the state-of-the-art theoretical value of 1.995 348 958 0(17), which includes QED contributions up to the two-loop level of the order of (Z alpha)(2) and (Z alpha)(4) and represents a stringent test of bound-state quantum electrodynamics calculations.