PURPOSE: To make a work holdable on the supporting surface of a seat base without any slipperiness instead of using an engager, by setting the work immersibly inside the said seat base's supporting surface, while installing a presser to be closely pressed to one side of the work under the state of being immersed.

CONSTITUTION: A rotary shaft 13 is provided in a bracket 12 on a pallet 11, and a table 14 is connected to the tip part of the shaft 13. A seat base 18 supporting one side of a work and making up a cutting reference plane is clamped to the table 14. A presser 42 is clamped to the tip of a holding arm 32 and likewise another presser 46 is secured tightly to each of concave parts made up at plural positions inside the supporting surface of the seat base 18. The presser 46 is projected out of the supporting surface of the seat base 18 at freedom and elastically deformed under the state of supporting the work whereby it is immersed inside the supporting surface of the base 18 and can be closely pressed to one side of the work.