In this presentation, the electromechanical properties of carbon based nanodevices will be discussed. Before discussing our research, an introduction to the recent progresses on the ultra-sensitive mass and force detection methods using NEMS will be given. From this introduction it can be explained why carbon based nano structures including carbon nanotube and graphene are interesting materials in the NEMS research field. In the beginning of reporting our experimental works, our previous researches on the electromechanical properties and a possible application of carbon nanotubes will be reviewed. Carbon nanotube based nanorelay and its electromechanical measurement results and their applications will be introduced at first. …