An information processing device displays an NC machining program and a physical state of a machine tool that is operated based on the NC machining program. The information processing device acquires, during execution of a block in a machining block, data indicative of the physical state of the machine tool, associates the block that was being executed with the acquired data and stores the block and the data that have been associated. In addition, the information processing device refers to the database and draw the block using a color according to an intensity of the data, and displays the NC machining program.