A processing method of a work includes: forming flange bending parts at respective side parts of the work, the flange bending parts including first bending parts extending in a length direction of the work; holding a first part of the work in the length direction where the flange bending parts are formed between a die and a pad; and pressing a second part of the work in the length direction in a thickness direction to form a second bending part extending in a width direction of the work between the first part and the second part. The die includes a supporting surface supporting the work, a first relief part including a first inclined surface, and a second relief part including a second inclined surface.

A rotatable body is configured to be held to a holding surface of a holder in a non-contact state by an action of air, and a movable shaft having a same axial center as a rotation shaft. A leading end of the movable shaft directly faces an end of the rotation shaft. The movable shaft is housed in an insertion part of the holder so as to be movable in an axial direction. Centering is automatically performed by making a Bernoulli effect appear by the air flowing from a side of a first surface of the rotatable body opposite to a second surface of the rotatable body toward the second surface of the rotatable body through a space between an outer periphery of the movable shaft or an outer periphery of the rotation shaft and a peripheral edge of a mounting hole.

A processing method of a work includes: forming flange bending parts at respective side parts of the work, the flange bending parts including first bending parts extending in a length direction of the work; holding a first part of the work in the length direction where the flange bending parts are formed between a die and a pad; and pressing a second part of the work in the length direction in a thickness direction to form a second bending part extending in a width direction of the work between the first part and the second part. The die includes a supporting surface supporting the work, a first relief part including a first inclined surface, and a second relief part including a second inclined surface.