Abstract: A welding apparatus controlling a position of a welding arc, having a welding head housing an electrode producing the welding arc in a working zone. The apparatus has an electromagnet compensating a magnetic field in the working zone and at least two photoelectric elements, each of the elements having its viewing area. Viewing areas of photoelectric elements intersect forming a cross-view field. Photoelectric elements are electrically connected to each other in bridge and to the electromagnet. When the welding arc is strayed, the cross-view field is displaced, the bridge connection becomes unbalanced and a certain potential is supplied from the photoelectric elements to the electromagnet. When this potential is supplied to the electromagnet, it compensates the magnetic field in the working zone by returning the arc into a proper position.