PURPOSE: To read in much information even with a narrow bar code area by providing a means which separates the bar code drawn in three primary colors into individual monochromatic light and reads in these light.

CONSTITUTION: A light emitting part 6 consisting of a red light emitting part 1, a green light emitting part 2, and a blue light emitting part 3 and a light receiving part 4 are attached to one face of a case 16. When the red light emitting part 1 is lit and a bar code sheet 5 drawn in three primary colors and the case 16 are scanned by relative movement, the red light is reflected by only the base code drawn in red, and the reflected light is made incident on the light receiving part 4 to generate a photovoltaic current, and the current is converted to a signal by a decoding part 8. When the red light emitting part 1 is switched to the green light emitting part 2 by a read control part 7 and they are scanned again, the bar code drawn in green is read in. When the green light emitting part 2 is switched to the blue light emitting part 3 and they are scanned, the bar code drawn in blue is read in. Consequently, the information volume which is three times as large as that a conventional bar code is written.