A numerical control device is intended for a machine tool that machines a workpiece using a multi-edge tool including a plurality of edges of different specifications, the numerical control device including: a tool information memory that stores edge type numbers in association with tool type numbers; a tool type-edge type selection command decoding unit that prefetches a plurality of blocks of a machining program, decodes a tool type selection command for selecting one of the tool types and/or an edge type selection command for selecting one of the edge types in the plurality of prefetched blocks, and generates internal information including the tool type selection command and/or the edge type selection command that have been decoded; and a tool selection unit that selects one tool with which the number of times of tool replacement is minimized during execution of at least the plurality of prefetched blocks.