A solar simulator for solar cells is an important tool to
measure their performance. At present, xenon and halogen
lamp is used at most laboratories. It is considerably accurate,
but the facility is so large and so expensive. Therefore, a
solar simulator using LED (light-emitting diode) lamps is
proposed, that is low-cost and portable, and was invented to
its capability. Its capability was preliminarily evaluated by
examining an illuminance distribution using simulation. Although
a light inhomogeneity is one of the problems to be
solved, it was shown that an unevenness of illumination is
about 3%. Secondly, in terms of spectral property, absolute
spectral responses by plural usage of different LEDs were
also estimated. An overall measurement concept and procedure
by the LED simulator are discussed and proposed.