After measurement, light-emitting elements are temporarily numbered (1), . . . in measuring order and arranged successively on a temporary palette. In parallel with this operation, measured light intensity data are input to a computer system in association with the temporary numbers (1), . . . In the computer system, the measured light intensity data are rearranged according to predetermined algorithm to make the light intensity values of adjacent light-emitting elements substantially equal, so that the temporary numbers (1), . . . are rearranged on a memory in accordance with the rearranged data. The rearranged data are sent from the computer system to a robot, so that the light-emitting elements on the temporary palette are arranged on a taping.