Milling machines are machine tools designed to machine solid metal or other hard materials.  The milling machine is often splits into two categories depending on the orientation of the spindle cutting tool, either vertical or horizontal.  Both types are available in small machines that can be mounted on a bench to room-sized milling centres, although the vertical milling machine is more suited to larger applications.

Milling machines can be used for a vast number of operations, from simple slot and keyway cutting, to more complex operations such as contouring or diesinking.  The heavier cutting operations may generate large amounts of excess heat, so often a fluid can is pumped to the cutting site to lubricate and cool down the cut.

Unlike a drill press where the drill moves axially to cut the workpiece, which is held stationary, milling machines can also move the piece radially against the rotating milling cutter, which can cut both on its tip and on its sides.