A binding machine, includes: an accommodating portion configured to accommodate a wound binding tape; a main handle; and a clincher arm. The accommodating portion includes, with the wound binding tape in an accommodated state, a side wall portion that faces a side surface of the binding tape, and a circumferential portion that is continuous with the side wall portion, faces a front surface of the binding tape, and is provided with an opening for accommodating the binding tape in a part of the circumferential portion.