PURPOSE: To make a titled device smaller in size and welding performance extremely high in circumferential welding of pipes by providing a selecting device for independent controlling of TIG welding and MIG welding and continuous sequence controlling.

CONSTITUTION: A controller 20 for automatic welding 20 consists of a control circuit 21 and switches 22, 23, of which switch 22 is for selecting the continuous sequence controlling of TIG welding and MIG welding and independent controlling thereof. More specifically, if the switch 22 is shifted to the position A, the TIG welding and the MIG welding are controlled continuously sequentially, and when it is shifted to the position B, the TIG welding and the MIG welding can be sequentially controlled respectively independently. The switch 23 is for selecting the TIG welding and the MIG welding, and is effectively only when it is shifted to the position B, that is, for the case of controlling the TIG welding and the MIG welding respectively independently.