To provide a sheet material cutting device which prevents a sealing sheet from being entangled to side edges in a sheet extending direction of a cutting table.

In the structure of the sheet material 8 cutting device 1, the cutting table 14 made of bristles 10 is set up so as to be movable along the sheet material extending direction, and the sheet material 8 is placed on an upper surface of the cutting table 14. Then the sheet material 8 is covered with the non-permeable sealing sheet 9, and cut to a preset shape while being sucked to and held on an upper surface of the cutting table 14, together with the sealing sheet 9. The cutting device 1 is provided with permeable endless belts 7 which cover both side edges along the sheet material extending direction over the entire length of the cutting table 14, and thus the sealing sheet 9 is sucked and held via the endless belts 7 by suction force working on the upper surface of the cutting table 14. In this manner the endless belt 7 can travel integrally together with the cutting table 14.