To provide a step-in/snow board binding for holding boots on a side surface.

This binding comprises at least one jaw-like part 2 fixed to a driving arm 9 driven by the boots. The jaw-like part 2 has a pedal 9 operating in cooperation with a pin 12 as a locking means, and the pedal 9 can move along a guide slot 13 so as to lock the jaw-like parts 2 and 3 at various positions. The binding has a return spring 58 energizing the jaw-like part 2 to be kept in an opened state, and a means for keeping the pin 12 away from a lock position when the jaw-like part 2 rises. The jaw-like part 2 does not close carelessly, and the pin 12 as the locking means does not disturb the closing operation.