To provide a jumping power measuring instrument to be used when measuring jumping power and safely and easily measuring particularly running jumping power, which has been difficult to measure with free movement by a conventional jumping power measuring instrument.

The measuring instrument is constituted by installing a base 1 and a required number of chains 2 in the ladder-like positions of the base, inserting a string in the front face of the chains while inserting a rubber plate string 4 in the back face of the chains, and firmly fixing the rubber plate string, without fixing the string so as to be freely movable.