A numerical control device including a collision determining unit that detects a possibility of collision between a machine and an area set as an entry prohibited area; an operation-continuation instructing unit that instructs whether to continue an operation when the collision determining unit detects the possibility of collision and shaft movement is temporarily stopped; a machining-information storage unit that stores internal operation information of the numerical control device regarding the temporary stop when the operation-continuation instructing unit instructs continuation of the operation; and a collision-determination processing unit that invalidates a collision determination on the basis of the operation information stored in the machining-information storage unit when executing the same machining program the next and subsequent times.