A device includes: a cylindrical body (11) formed of an elastic material and a slit (21) formed along a longitudinal direction of the cylindrical body (11) from one end to an opposite end of the cylindrical body (11), a distal end of a nail (1) being inserted to be held in the slit. The cylindrical body (11) includes: plural pairs of holding teeth (13) plurally divided in the longitudinal direction of the cylindrical body (11) by dividing grooves (12) formed from the slit (21) along a circumferential direction of the cylindrical body (11) such that the holding teeth (13) of each pair are opposed to each other across the slit to hold the distal end of the nail and coupling pieces (14) configured to couple adjacent ones of the holding teeth (13) on an opposite side of the slit.
