In a semiconductor element comprising microcrystalline semiconductor, a semiconductor junction is provided within a microcrystal grain. Further, in a semiconductor element comprising microcrystalline semiconductor, microcrystal grains of different grain diameters are provided as a mixture to form a semiconductor layer. Thereby, discontinuity of a semiconductor junction is lessened to thereby improve the characteristics, durability, and heat resisting properties of a semiconductor element. Distortion in a semiconductor layer is also reduced.