A nanotube probe assembled under real-time observation inside an electron microscope, the probe including a nanotube; a holder for holding the nanotube; and a fastening means for fastening the nanotube at a base end portion thereof to the holder; and the tip end portion of the nanotube protrudes from the holder. The method for manufacturing a nanotube probe includes the steps of setting up a nanotube and a holder inside an electron microscope; allowing a base end portion of the nanotube, with a tip end portion thereof protruding, to come into contact with the holder; and irradiating electron beam to the base end portion of the nanotube to form a carbon film at the base end portion of the nanotube, or forming a fused part at the base end portion of the nanotube, thus fastening the base end portion of the nanotube to the holder by the carbon film.