Abrasive machine

An abrasive machine, comprising:

• an abrasive plate;
• a plate holder holding said abrasive plate;
• a fixed engaging member being formed into a ring shape and fixed to said plate holder, said fixed engaging member engaging with an outer edge of said abrasive plate;
• a first O-ring being provided between a pressing face of said fixed engaging member and an upper face of said abrasive plate, said first O-ring separating the pressing face of said fixed engaging member from the upper face of said abrasive plate;
• a second O-ring being provided between an upper face of said plate holder and a lower face of said abrasive plate, said second O-ring separating the upper face of said plate holder from the lower face of said abrasive plate;
• and
• a fluid supply-discharge mechanism for supplying a fluid to and discharging the same from a zone enclosed by the lower face of said abrasive plate, the upper face of said plate holder and said second O-ring, said fluid supply-discharge mechanism changing a shape of an abrasive face of said abrasive plate by changing pressure of the fluid,
• wherein an outer circumferential face of said abrasive plate is separated from an inner circumferential face of said fixed engaging member.