Disclosed is a device for sheet insertion includes: a cylindrical mantle tube of which the front and back ends are opened and the inside is formed to be a sheet receiving part and an extruding member for sheet extrusion that is inserted into the mantle tube in a state of moving in a back and forth direction that is a tube-axis direction and of rotatable, wherein the extruding member has a shaft having a longer length than that of the mantle tube and a forked sheet winding part disposed at a tip portion of the shaft, and axial slits having a size enough to insert the sheet are formed therethrough on walls facing each other at the front end of the mantle tube over approximately the same length as that of the sheet winding part.