Lifetime prediction device and machine tool

A lifetime prediction device that predicts a lifetime of a filter configured to filter a liquid used in a machine tool, the lifetime prediction device comprising:

• a pressure acquisition unit configured to acquire a pressure value of the liquid applied to the filter in time sequence based on a signal output from a pressure sensor;
• a time acquisition unit configured to acquire a machining time of a prescribed machining that is predetermined, based on information indicating an operating state of the machine tool;
• a calculation unit configured to calculate an amount of pressure change during the machining time, based on the pressure value acquired in time sequence;
• and
• a prediction unit configured to predict a lifetime which is a remaining time before a pressure of the liquid applied to the filter reaches an upper limit value, by using the pressure value at a time point when the prescribed machining has been completed, the machining time, and the amount of pressure change.