A numerical control device includes an NC-machining-program reading unit to read an NC machining program, a machining-removal-shape generation unit to generate a machining removal shape by a block of the NC machining program, a tool-data search unit to search for tool data to be used in the NC machining program, and a machining-finished-shape generation unit to generate a machining finished shape from the machining removal shape generated by the machining-removal-shape generation unit. During editing of the NC machining program, the machining removal shape and the machining finished shape can be confirmed sequentially by the block.