In this study, a method for observing the internal pore structure of a ceramic powder compact using micro-X-ray computed tomography (micro-CT) was examined. Powder compacts have low densities, which makes it difficult to distinguish the low-density structures and large pores. In this study, the effect of a contrast agent (potassium iodide solution) on micro CT images was examined. First, the powder compact was made by die-pressing using alumina granules. Then, the powder compact was immersed into the contrast agent in a vacuum. As a result, the large pores in the powder compact were emphasized as white areas in the images.