A molded product from a mold, the mold for molding a molded product in a
desired shape can be designed with high precision by correcting a shape
change of the molded product. A mold in which use surfaces of an upper
mold and a lower mold are formed to be design curved surfaces of an
optical lens is prepared. A curved surface shape of the optical lens
molded from this mold is measured, and a measured value is approximated
by equation (1). The curved surface of the optical lens specified by the
equation and a design curved surface are compared to obtain an error
between both the curved surfaces. Information corresponding to the error
is used as correction information, and the use surfaces in the upper mold
and the lower mold are corrected and
designed..times..times..rho..times..times..rho..times..times..times..rho.-
.times. ##EQU00001##