A shaped reflector antenna has a low tolerance to its various fabrication errors because its specific reflector shape needs high precision on the order of optical wavelength. This paper proposes a new design of optical antenna with a high tolerance against manufacturing errors by shaping a feeder-lens and a sub-reflector. Antenna parameters are optimized for each error and optical gain degradation. We compared the error tolerance of our optical antenna, a standard Cassegrain optical antenna, and a normal shaped reflectors optical antenna. The new optical antenna has better error tolerance than the normal shaped reflectors optical antenna and is competitive with the standard Cassegrain optical antenna. The designed new antenna's surface is so simple that the required manufacturing precision has become realistic.