Writing instrument

A writing instrument comprising:

• a shaft barrel;
• and
• a grip provided at part of the shaft barrel, wherein
• the grip has a cylindrically shaped inside shaft part and a cylindrically shaped outside shaft part arranged at an outside of the inside shaft part, thinner than the inside shaft part, and comprised of a nonviscoelastic plastic and a space part is provided between the inside shaft part and the outside shaft part,
• the outside shaft part is elastically deformable in a diametrical direction, and
• deformation inward in the diametrical direction of the outside shaft part is restricted by an inside surface of the outside shaft part abutting against an outside surface of the inside shaft part.