To provide a collision shock absorbing material having always adequate shock absorbing function regardless of different working conditions including colliding strength.

The collision shock absorbing material 10 is arranged on each of the collision faces of a pair of members having colliding motion. It comprises a base plate part 12 formed of an elastic material and arranged on one collision face, a protruded part 14 protruded from the surface of the base plate part 12 to the other collision face, a space part 16 recessed from the reverse of the base plate part 12 to the inside at a position corresponding to the protruded part, and an inside boss 18 provided inside the space part 16 and protruded from the bottom of the space part 16 to the opening side.