Near-field electromagnetic loss of electroplated copper layers has been characterized for applications to multichip microsystems with on-chip electromagnetic protection. Copper layers in the thickness range of 0.2 μm-200 μm have been electroplated on Pyrex glass substrates. A pair of microwave transceivers 3.5 mm x 3.5 mm in size has been fabricated using electroplated nickel microloop antennas. An electromagnetic radiation loss of 10 dB-40 dB has been measured from the copper layers in the thickness range of 0.2 μm-200 μm for the wave bandwidth of 100 MHz - 1 GHz. The 0.2-μm-thick copper layer provides a shield loss of 20 dB at frequencies higher than 300 MHz while showing a predominant decrease of shield loss to the 10 dB level at lower frequencies. No substantial increase of shield effectiveness has been observed for copper shield layers thicker than 2 μm.