Abstract: An engine driven arc welder including a welding generator driven by an engine; output circuits for controlling the output of the welding generator in accordance with a control signal and for delivering the output to welding output terminals; a current detector for detecting the current flowing in the welding output terminals; an error detector for comparing the output of the current detector with a reference signal to detect error; a control signal producing circuit for producing the control signal in accordance with output of the error detector and for delivering it to the output circuit; and a voltage detector R10, VR10 for detecting voltage to be delivered to the welding output terminals, wherein the arc welder has a welding output characteristic having a constant current control arc characteristic in accordance with the reference signal and which exhibits a drooping characteristic in the vicinity of the arcing voltage and which is capable of increasing the current when the arc voltage is lowered.