Abstract: A temperature rise value estimating method for a machine tool including a cooling apparatus configured to cool a specific portion and a plurality of sensors. The temperature rise value estimating method includes: determining a cooling state of the specific portion by determining whether the cooling apparatus is in an operating state or a stopped state and determining whether a time measured from a base point of an activation or a stoppage of the cooling apparatus has elapsed a predetermined delay time or not; selecting an estimation model corresponding to the determined cooling state of the specific portion from a plurality of estimation models prepared in advance corresponding to different cooling states of the specific portion; and calculating an estimated temperature rise value of the specific portion based on the selected estimation model and temperature data derived from a measured value acquired by the plurality of temperature sensors.