This paper intends to report the possibility of using an light-emitting diode (LED) as a light source of a solar simulator for measuring solar cells. In our laboratory the LED solar simulator has been made up as the test production, and characteristics of monocrystalline Si solar cell have been measured by using it. As a result, spectral response (SR) and I-V characteristics of solar cells can be measured by the proposed method even though light intensity of the LED is in the range of approximately up to 10 mW/cm(2). Moreover, I-V characteristics under standard test conditions (STC) can be estimated by compensation. (c) 2006 Published by Elsevier B.V.