In order to clarify the effect of particle shape on the mechanical properties of powders, such as compaction and flow, the centrifugal compaction test, the tensile test, the direct shear test and Carr's flowability test were carried out on several kinds of fine powders having various particle shapes. Introducing the concept of "apparent adhesion, " the effect of particle shape on the porosity, was examined. It was found that the porosity of a powder bed diminished as the sphericity of the particles increased. The flow properties were also affected by particle shape. With increasing shape factor, the flowability increased.