A mask pattern formation method and apparatus capable of performing OPC and lithography verification and obtaining OPC result, and a lithography mask are provided. The method of forming a mask pattern from a design layout of a semiconductor integrated circuit comprises inputting a design layout, performing first OPC on the design layout, calculating a first evaluation value for a finished planar shape of a resist pattern corresponding to the design layout based on the first OPC, determining whether the first evaluation value satisfies a predetermined value, if the first evaluation value does not satisfy the predetermined value, locally altering the design layout, performing second OPC on the altered design layout, calculating a second evaluation value for the altered design layout, performing second determination, and if the second evaluation value satisfies the predetermined value, outputting the result of OPC and the first and second evaluation values.