A lead wire cut-and-clinch apparatus cutting a protruding portion of a lead wire of an electronic-circuit-component inserted into a through-hole of a circuit board and protruding toward a back surface side of the circuit board to a set length and bending the protruding portion along a back surface of the circuit board, comprising: a pair of fixed pawls including first blades on respective tip surfaces; a pair of movable pawls capable of moving along the respective tip surfaces of the fixed pawls and including respective second blades shearing the lead wire in conjunction with the respective first blades; a pawl set clearance changing device for changing a clearance of two sets of pawl sets each having the fixed pawl and the movable pawl; a movable pawl driving device for causing the first blades and the second blades to shear and bend the lead wire by relatively moving the movable pawls with respect to the fixed pawls in the two respective sets of pawl sets; the lead wire cut-and-clinch apparatus further comprising respective contact members which are fixed, in a state of being electrically insulated from the respective fixed pawls by electrical insulating layers, to parts of the respective fixed pawls and are distanced, with respect to the respective tip surfaces, to the opposite side of the side along which the respective movable pawls are configured to move; an advance pawl set clearance control section allowing the respective contact members and the respective lead wires to approach each other by causing the pawl set clearance changing device to change the pawl set clearance by a set distance after insertion of the lead wires between the respective first blades and second blades and before a movement of the movable pawls by the movable pawl driving device in a state where a position of the pawl set is at a set position; and a pair of detecting circuits formed between the respective contact members and fixed pawls, usually remaining in an open state, and being put into a closed state by the respective contact members and fixed pawls being electrically connected across the insulating layers by the respective lead wires inserted between the respective first blades and second blades. a pair of fixed pawls including first blades on respective tip surfaces; a pair of movable pawls capable of moving along the respective tip surfaces of the fixed pawls and including respective second blades shearing the lead wire in conjunction with the respective first blades; a pawl set clearance changing device for changing a clearance of two sets of pawl sets each having the fixed pawl and the movable pawl; a movable pawl driving device for causing the first blades and the second blades to shear and bend the lead wire by relatively moving the movable pawls with respect to the fixed pawls in the two respective sets of pawl sets; the lead wire cut-and-clinch apparatus further comprising respective contact members which are fixed, in a state of being electrically insulated from the respective fixed pawls by electrical insulating layers, to parts of the respective fixed pawls and are distanced, with respect to the respective tip surfaces, to the opposite side of the side along which the respective movable pawls are configured to move; an advance pawl set clearance control section allowing the respective contact members and the respective lead wires to approach each other by causing the pawl set clearance changing device to change the pawl set clearance by a set distance after insertion of the lead wires between the respective first blades and second blades and before a movement of the movable pawls by the movable pawl driving device in a state where a position of the pawl set is at a set position; and a pair of detecting circuits formed between the respective contact members and fixed pawls, usually remaining in an open state, and being put into a closed state by the respective contact members and fixed pawls being electrically connected across the insulating layers by the respective lead wires inserted between the respective first blades and second blades.