To provide a safety device for a vehicle capable of effectively reducing an impact load applied to a collision object when colliding with the collision object, by coping with many collision patterns.

In this safety device 10 for the vehicle, when preparing a collision, since an impact absorbing member 14 is changed to an optimal collision preparing state corresponding to a relative speed of the collision object 100 to the vehicle 12, mass of the collision object 100, a form of the collision object 100 and the collision direction of the collision object 100 to the vehicle 12, the safety device can cope with many collision patterns when the collision direction of the collision object 100 becomes the oblique front of the vehicle, when the relative speed of the collision object 100 to the vehicle 12 is fast and when mass and a form of the collision object 100 are large. When colliding on the collision object 100, equivalent impedance (hardness) of the impact absorbing member 14 is increased and decreased in a crest shape by using the internal force effect of the impact absorbing member 14. Thus, the impact load of the collision object 100 can be effectively reduced by the impact absorbing member 14.