A family of fulleren including C₆₀ and in addition carbon nanotubes have been discovered as new allotropes of carbon at the final stage of 20th century. These materials are characterized not only in terms of small sized shapes but also of unique electronic, electrical and mechanical properties, which are not possessed by well known carbon materials, graphite and diamond. Especially, nanotubes have several advantages to be used as the probes for scanning probe microscopy. Recently, we have developed a well controlled process to bring about carbon-nanotube probes for practical devices. The process consists of electrophoresis of the nanotubes we developed previously and handling nanotubes in a scanning electron microscope equipped with two individual manipulatable stages. In this article, we review how nanotubes have been applied to scanning-probe-microscope probes and what have been observed by the new devices, and also view a future scope in this field.