To easily manufacture a prism ballast-type contact lens in a simplified process without the preparation and management of a plurality of molds and to provide the mold which is advantageously used in the manufacturing.

In the mold, a male mold 12 has a convex cavity face 16 provided with the cavity face of a form corresponding to at least an optical part at the rear face of a lens and a female mold 14 has a convave cavity face 20 provided with the cavity face of a form corresponding to at least a lower part in front of the lens giving a slab off area. In a molding cavity 12, formed by fitting the male mold 12 and the female mold 14, of a size giving the lens blank of thickness where at least the optical part in front of the lens can be obtained with machining, prescribed lens raw material is polymerized and the optical part in front of the lens blank is machined. Thus, the contact lens is obtained.