A lens-mold producing method comprising: a position and posture determining step of specifying positions and postures, in space coordinates, of a first mold having a molding surface R 1 for forming one optical surface of a lens and a second mold having a molding surface R 2 for forming the other optical surface; a mold holding step of rotating and/or inclining, based on the positions and postures in the space coordinates, at least one of the first mold by a first jig and the second mold by a second jig, maintaining a rotation angle and/or an inclination angle of a reference plane of the first mold with respect to a reference plane of the second mold, and holding the first mold and the second mold; and an assembling step of arranging the molding surface R 1 of the first mold and the molding surface R 2 of the second mold so as to face each other, fixing outer peripheries of the first mold and the second mold, and assembling a lens-mold, wherein the position and posture determining step is performed while the first mold is being placed on a first jig and the second mold is being placed on a second jig, the first jig including a first placing portion and a first gripping portion, and the second jig including a second placing portion and a second gripping portion; and wherein the first placing portion and the second placing portion each have a shape and configuration capable of placing the first mold and the second mold respectively; and the first gripping portion and the second gripping portion are configured to grip and fix outer peripheries of the first mold and the second mold respectively; characterized in that the mold holding step comprises maintaining, by a first mold holder and a second mold holder each having three or more supports (311, 321) and a suction portion (312, 322), the rotation and/or the inclination of the first mold and the second mold with the respective supports and suction portion. a position and posture determining step of specifying positions and postures, in space coordinates, of a first mold having a molding surface R 1 for forming one optical surface of a lens and a second mold having a molding surface R 2 for forming the other optical surface; a mold holding step of rotating and/or inclining, based on the positions and postures in the space coordinates, at least one of the first mold by a first jig and the second mold by a second jig, maintaining a rotation angle and/or an inclination angle of a reference plane of the first mold with respect to a reference plane of the second mold, and holding the first mold and the second mold; and an assembling step of arranging the molding surface R 1 of the first mold and the molding surface R 2 of the second mold so as to face each other, fixing outer peripheries of the first mold and the second mold, and assembling a lens-mold, wherein the position and posture determining step is performed while the first mold is being placed on a first jig and the second mold is being placed on a second jig, the first jig including a first placing portion and a first gripping portion, and the second jig including a second placing portion and a second gripping portion; and wherein the first placing portion and the second placing portion each have a shape and configuration capable of placing the first mold and the second mold respectively; and the first gripping portion and the second gripping portion are configured to grip and fix outer peripheries of the first mold and the second mold respectively; characterized in that the mold holding step comprises maintaining, by a first mold holder and a second mold holder each having three or more supports (311, 321) and a suction portion (312, 322), the rotation and/or the inclination of the first mold and the second mold with the respective supports and suction portion.