Spunbonded nonwoven fabric for filter and method for producing same

Provided is a spunbonded nonwoven fabric for a filter, the spunbonded nonwoven fabric comprising a composite polyester fiber in which a low melting point polyester having a melting point 10-40°C lower than the melting point of a high melting point polyester is disposed around the high melting point polyester, wherein the spunbonded nonwoven fabric has a surface layer portion and a back layer portion, the single fiber fineness of the composite polyester fiber in the surface layer portion is at least 1 dtex and less than 3 dtex, the single fiber fineness in the back layer portion is 3-5 dtex, and the basis weight of the spunbonded nonwoven fabric is 130-300 g/m2. The spunbonded nonwoven fabric for a filter has high stiffness and air permeability in a thick fineness layer as well as excellent dust resistance in a thin fineness layer.