A method of producing a curved surface includes a step of inputting section data on two sections (11, 12) of a three-dimensional curved-surface object, data on first and second section curves (11a, 12a) formed by the two sections (11, 12), respectively, and data on a three-dimensional curve (31a) which includes points (P1, P1') on the first and second section curves, respectively, and specifies the outer shape of the three-dimensional curved-surface object; a step of generating an intermediate section (41) for each of division points (Si) (i = 1, 2, 3 ... ) which divide the three-dimensional curve (31a) into a large number of line elements, each intermediate section (41) including the corresponding division point; a step of calculating an intermediate section curve (41a) of each intermediate section using the data on the two section curves (11a, 12a) and positional information about the division points (Si); and a step of generating the curved surface of the three-dimensional curved-surface object using this set of a plurality of intermediate section curves.