An object is to reduce a cycle time for fabricating a low rolling resistance pneumatic tire and to provide the same pneumatic tire. As a means therefor, in building a tread portion by winding spirally a rubber strip material whose cross section is divided into a first region made of a conductive rubber and a second region made of a non-conductive rubber in a tire circumferential direction in a partially overlapping fashion by the use of an extruding machine which extrudes continuously the rubber strip material, an area ratio of the first region relative to the cross section of the rubber strip material is made to change in a tire width direction.