A wire bonding apparatus includes a heat block and a heat plate provided on the heat block. A recess is provided in the heat plate to receive the first semiconductor chip and wires without contact therewith when the lead frame is provided on the heat plate such that the first main surface of the lead frame faces toward heat plate. A duct is provided in the heat plate to connect the recess to the outside of the heat plate. A gas supplied through the duct is heated by a heater and discharged into the recess.