To separate and feed various kinds of sheet materials by improving the separation performance in sheet material separation to enlarge the range of stiffness of a separable sheet material.

In a sheet material feeder comprising a separating claw 8 (separating member) brought into contact with the uppermost surface corner part of a sheet material S and a paper feed roller 5 (feeding means) for separating sheet materials S stopped by the separating claw 8 one by one and feeding the same by a circular arc contacting part 23 brought into contact with the uppermost surface of the sheet materials to be moved in the conveying direction, the paper feed roller 5 starts to be brought into contact with a sheet material S with a region of the circular arc contacting part 23 separated form the separating claw 8 and gradually brings a region of the circular arc contacting part 23 closer to the separating claw 8 into contact with the sheet material.