In this paper, the authors investigated the reflection and absorption characteristics of a general photovoltaic (PV) module. As a result, the electromagnetic waves could be attenuated only 6dB in typical PV module. However, if the PV module is installed in the outer wall of buildings, electromagnetic interference is caused by the surroundings. To reduce this electromagnetic interference, the authors suggested a method to absorb electromagnetic wave using multiple PV modules that have deference impedance, and simulation was performed. As a result, it was confirmed that using a typical PV module and the PV module including electronic device, the reflection waves of those PV modules could be attenuated up to 12 dB. (C) 2002 Elsevier Science B.V. All rights reserved.