According to one embodiment, a sheet material cutting device includes a rotatable blade including a blade unit, which extends from one end of the rotary shaft to the other end thereof and defines a predetermined angle relative to an axial direction of the rotary shaft, provided on the outer circumference of a rotary shaft rotatably supported by a support frame. The sheet material cutting device further includes a fixed blade mounted on the support frame so as to be opposed to the rotatable blade and configured to cut a sheet material in a transverse direction perpendicular to the feed direction of the sheet material that is perpendicular to the axial direction of the rotary shaft. The sheet material cutting device further includes a sheet-suspension prevention unit configured to prevent a rear edge of the sheet material in its feed direction from being suspended within the support frame.