  The MAGIC Collaboration is building a second telescope, MAGIC II, improving
the design of the current MAGIC Telescope. MAGIC II is being built at 85 m of
distance from MAGIC I, and will also feature a huge reflecting surface of ~240
m$^2$ of area. One of the improvement is the design for the mirror of MAGIC II,
that are lighter and larger, being square of 1 m of side and weighting around
15 kg. For the development and production of the new mirrors, two different
techniques, both reliable and affordable in price, were selected: the diamond
milling of aluminium surfaces and the cold slumping of thin glass panes. As
tests for the second one are still ongoing, we present a description of the
diamond milling technique, and its application and performance to the produced
mirrors.
