The iodine stabilized He-Ne laser at 633 nm is widely used as the national length (wavelength) standards in many countries. Since the wavelength emitted by the laser is directly proportional to the cavity length of the laser, extremely high mechanical stability is necessary for the cavity of the iodine stabilized He-Ne laser. Many special parts as well as special materials are adopted to achieve a sufficiently high stability in the conventional iodine stabilized He-Ne lasers while the adoption of such special parts and materials brings difficulty in the maintenance of the lasers. I developed and constructed a new iodine stabilized He-Ne laser with a special mechanical design. The assembly and adjustment of the laser is quite easy. Although most parts and materials of the laser are commercially available, it showed better stability especially against the ambient temperature variation. The new iodine stabilized He-Ne lasers were used for a long time as the national length standards of Japan.