1. An image reading apparatus comprising a first laser stimulating ray source for emitting a laser beam having a wavelength of 633 nm or 635 nm, a second laser stimulating ray source for emitting a laser beam having a wavelength of 470 to 480 nm, a laser beam scanning means for scanning a laser beam, at least one light detecting means for photoelectrically detecting light released from an image carrier carrying an image, and at least one filter means disposed in front of the light detecting means and having a plurality of filters for transmitting light of different wavelengths.