There are disclosed multi-crystalline silicon which is added with Ga (gallium) as a dopant and a method for producing Ga-doped multi-crystalline silicon, which comprises adding Ga to silicon melt in a crucible, which is melted by heating, and cooling the silicon melt to allow growth of multi-crystalline silicon. According to the present invention, there are provided multi-crystalline silicon and a multi-crystalline silicon wafer for producing solar cells showing stable conversion efficiency for light energy without causing photodegradation as well as methods for producing them.