A collision detecting apparatus has a plurality of collision detecting means and a determination means for determining a collision based on at least one of outputs of the plurality of collision detecting means. Each of the collision detecting means has a crank member and a deformation detecting member disposed at the center of a middle portion of the crank member for detecting a deformation of the middle portion. Each of the crank member has a first extending portion extending from a first end of the middle portion and a second extending portion extending from a second end of the middle portion in a direction opposite to the first extending portion. A first collision detecting means and a second collision detecting means are arranged in opposite directions between a reinforcement member and one of side members.