A stopper for a keyboard-based musical instrument is provided for accomplishing a good stopping feeling of a pivotable member, thereby making it possible to improve a touch feeling and restrain collision noise and other noise. A stopper 7 for a keyboard-based musical instrument with which a pivotable member 6 comes into contact while said pivotal member pivotally moves in association with a key touch, thereby restraining the pivotal movement of said pivotable member 6, comprises a mass 26, a first cushion 25 laminated on a front side of said mass 26, and a second cushion 27 laminated on a back side of said mass 26. Preferably, the mass 26 is made of a metal, and the first cushion 25 is harder than the second cushion 27.