To provide a bird-preventing tool capable of exhibiting excellent semipermanent bird-preventing performance, and hardly damaging the beautiful appearance of a building.

This bird-preventing tool has a plurality of long-needle members and a plurality of short-needle members stood on a base part so as to be alternatively installed, and is characterized in that the interval between the neighboring long-needle member and the short-needle member is a prescribed distance, e.g. about 15 mm, which can exhibits the bird-preventing performance and can prevent the bird which is the target to be prevented, from being skewed. The prescribed height of each of the long-needle member and the short-needle member is the one capable of being prevented from being bent by the weight of the bird of the target to be prevented. For example, preferably the long-needle member has about 50 mm length and the short-needle member has about 30 mm length.