A collision detection device is provided with a load detection member 2 for detecting a collision load in a collision, and a mold member 3 which is molded to be integral with the load detection member 2. The mold member 3 covers at least the surface of a collision side of the load detection member 2, to absorb at least a part of impact energy in the collision by a resilient deformation of the mold member 3. Thus, the collision detection device is substantially resistant to an impact in the collision, while being simply manufactured.