A glass substrate manufacturing method of the present invention comprises forming a multi-porous structure layer which comprises nano-size pores at a surface of a glass substrate by etching the surface of the glass substrate with hydrofluoric (HF) acid or an etchant substituting for fluoride. Unlike related art methods, the glass substrate forms no additional coating layer, uses no harmful chemical material, and is given anti-reflection, anti-fogging, and super-hydrophilic characteristics through a simple process at a relatively low temperature. The glass substrate is effectively applied to various applications requiring high light transmission such as a protective filter for a display device, a solar cell, a mobile communication device, glass of a building structure, and an optical element lens.