A numerical controller controls a machine having at least one axis based on at least one program. The numerical controller includes an actual machining time measuring unit that measures an actual machining time which is an actual time taken for execution of at least one block included in the program and a display unit that generates display data indicating a relation between the block and the actual machining time of the block.

Provided is a machining time prediction device including a predicted machining speed table where predicted machining speeds are registered in association with shape groups used for classification based on a shape of a machining path, a machining path generation unit generating machining path data including the machining path based on the program, a shape group determination unit determining which shape groups partial machining paths belong to, a path length addition unit adding and summarizing path lengths of the partial machining paths for the respective shape groups, a predicted machining time calculation unit calculating predicted machining times of the respective shape groups on the basis of a predicted machining speed table and the path lengths of the respective shape groups, a predicted machining time summation unit calculating a predicted machining time of the machining path by adding the predicted machining times of the respective shape groups, and a display unit displaying the predicted machining time of the machining path.

An NC machine tool is provided with a display device capable of displaying processing time individually for each function command of a block of an NC program. The display device of the NC machine tool is capable of displaying processing time for each function command. Thus, an operator is able to identify processing time for each function command via the display device.