In the post-genome era, the importance of cell analysis is increasingly appreciated since the cell is the minimum unit of the life phenomena. On-chip manipulation and measurement of biological cells are recognized to be an important subject for the establishment of novel analytical tools and methodologies for the forthcoming new cell biology. In this paper on-chip manipulation of biological cells and microparticles by means of dielectrophoresis and on-chip detection of single biological cells by ac impedance spectrometry have been investigated using microfulidics devices with embedded microelectrodes which were fabricated by LSI compatible microfabrication technologies.