PURPOSE: To provide a spike pin going inside and outside mechanism to make a spike pin go inside and outside of a ground contact surface of a tire so as to be used while being embedded in the tire.

CONSTITUTION: A spike pin 20 and a plug body 30 are inserted respectively slidably freely in the tip and the rear part of a pipe 10a being embedded in a tire, and these are connected to each other by a connecting bar 40 inserted in the pipe 10a. Lubricating oil 50 is filled in the pipe 10a. At the same time, a moving means 60 is provided to move the plug body 30 longitudinally in the pipe 10a, and the plug body 30 is moved longitudinally in the pipe 10a by the moving means 60 together with the spike pin 20 connected to it through the connecting bar 40, and the tip of the spike pin 20 is made to go inside and outside of the tip of the pipe 10a.