An electrostatic painting device capable of performing a painting while maintaining the spraying distance of an electrostatic painting machine within an optimum distance range with excellent coating efficiency, comprising an electrostatic spray gun (2) having a high voltage generating part (201) for applying a high voltage to an atomized paint, a detection means (107) for detecting a load current (I) varying according to a variation in spraying distance (L) between the electrostatic spray gun (2) and a painted object (4), a processing means (107) having the threshold of a load current value corresponding to the maximum spraying distance within the optimum distance range and outputting a warning signal when the detected load current lowers to the threshold or below, and a warning means (108) receiving the warning signal for warning and displaying, whereby the spraying distance is prevented from being increased beyond the optimum distance range unintentionally by a painter.