The nano-gripper of the present invention comprises (i) a pair of arms 71
and 71 disposed side by side, each arm 71 having a face at its front end,
the front-end faces of the arms 71 and 71 facing each other, (ii) and a
protrusion 72 with a tip formed on the front-end face of each arm, the
tips of the protrusions 72 and 72 facing each other, the radius of
curvature of each tip being 50 nanometers or less. Each protrusion 72 is
a triangular-pyramidal silicon crystal with (001), (100), and (111) side
faces.