A method for forming a carbonaceous material protruding structure, which includes a process of coating a diamond board (10) with a resist (11), a process of opening a hole (12) on the resist (11) applied and processing a wall (12b) of the hole (12) to reversely taper it from an opening part (12a) to a bottom side, a process of depositing a mask material from the side of the opening part (12a) and forming a mask deposit (14) inside the hole (12), a process of lifting off the mask material (13) deposited on the resist (11) with the resist (11), and a process of etching the diamond board (10) using the mask deposit (14) as a mask and forming a carbonaceous material protrusion. |