A blade sleeve 5 having an annular cutting edge 6 is formed at the distal end of a handle 1. A pressing body 9 is received in the blade sleeve 5 such that the pressing body 9 is allowed to move in the axial direction C. A contact portion 12 is formed at the distal end of the pressing body 9. The contact portion 12 may be located at a retracted position separated inwardly from the cutting edge 6 and a projected position F to which the pressing body 9 is moved from the retracted position, toward the cutting edge 6. When located at the projected position F, the contact portion 12 of the pressing body 9 is projected outward from the cutting edge 6. The pressing body 9 is movable between the retracted position and the projected position F and may be maintained at the retracted position or the projected position F. With the pressing body 9 maintained at the projected position F, a sample SE may be easily removed from the contact portion 12. By projecting from the cutting edge 6 at the projected position F, the contact portion 12 prevents the cutting edge 6 from being damaged, thus protecting the cutting edge 6.