A numerical control apparatus includes a machining-program reading unit that reads a command issued from a machining program, a command-path storing unit that stores a pre-compression command path in a pre-compression command path buffer, a compression processing unit that creates new one post-compression command path connecting start points and end points of a continuous plurality of pre-compression command paths, a movement-data creating unit that creates tool movement data necessary for correcting the post-compression command path to a tool movement path and interpolating the tool movement path, and an interpolation processing unit that interpolates the tool movement path and calculates a tool position using both the pre-compression command path stored by the command-path creating unit and the tool movement data of the tool movement path after compression created by the movement-data creating unit.