To prevent lowering of the precision of colorimetry caused by adhesion of powder, and to enable high-precision colorimetry by lighting pellets in a measuring container uniformly.

A cell 65 inside an integrating sphere 71 is filled up with pellets, through a hopper 63 from a cyclone 62 provided with a static eliminator 69 which removes electricity of pellets, along with removing powder by an ion air flow. A colorimetric apparatus which performs colorimetry by changing light led into the integrating sphere 71 into omnidirectional diffused light, illuminating the pellets inside the cell 65, and receiving its reflected lights with a photodetector 75 is obtained.