Automatic welding helmet ideal for TIG, MIG-MAG and MMA welding with darkening adjustment (DIN 9-13). The LCD liquid crystal filter automatically darkens when the welding arc is running and quickly returns to its transparent status when the arc is switched off; this means the operator doesnot need to lower and raise his mask during operations and and allows him to work always with both hands freely. It is not only fitted with a filter sensitivity adjuster depending on the welding process being carried out, but also has a 2-position external adjuster which can delay the time between darkening and lightening phases when the arc welding has been completed, according to the level of brightness of the piece.