To provide a handy binding tool capable of mechanical binding using a binding band, which binding tool has no internal driving source but is structured into an external drive binding tool, thus constructed relatively inexpensively.

The externally powered binding tool includes a tool body H which carries out a series of operations of sending out a band 1 and winding and tightening the band 1 around a binding object W to bind it up, a power supply unit K arranged separately to the tool body H, which power supply unit K can supply a driving force necessary for the series of binding operations to the tool body H, and a power transmission mechanism D which transmits power generated by the power supply unit K to a power input unit n of the tool body H. The power supply unit K is constructed as a manual pedal device having a step-in pedal 4.