The semiconductor device includes an oxide semiconductor film having a first region and a pair of second regions facing each other with the first region provided therebetween, a gate insulating film over the oxide semiconductor film, and a first electrode overlapping with the first region, over the gate insulating film. The first region is a non-single-crystal oxide semiconductor region including a c-axis-aligned crystal portion. The pair of second regions is an oxide semiconductor region containing dopant and including a plurality of crystal portions.