Vibration body for cutting, processing device, molding die and optical element

A vibration body for cutting comprising:

• a fixing portion for fixing a cutting tool for vibration cutting;
• and
• a vibration body main part for transmitting a bending vibration and an axial vibration to the cutting tool fixed to the fixing portion,
• wherein, with respect to a profile of a cross sectional plane perpendicular to an axial direction of the vibration body main part in a supporting base region which is a portion between a cross sectional plane perpendicular to the axial direction of the vibration body main part at a closest node position where a node closest to the fixing portion is located, the closest node being among nodes relating to the bending vibration formed in the vibration body main part and a cross sectional plane perpendicular to the axial direction of the vibration body main part at a cutting tool rear end position where an end of the fixed cutting tool, which is closest to the closest node position is located, a length of the profile in a direction perpendicular to a prescribed bending vibration direction of the vibration body main part is longer than a length of the profile in the prescribed bending vibration direction.