Numerical controller having function of automatically selecting parameter based on size of machining area

A numerical controller which controls a machine performing machining of a workpiece in a machining area, the numerical controller comprising:

• a parameter setting storage unit in which a setting value of a parameter used for control of the machine is set;
• a machining area estimation unit that estimates a size of the machining area based on the setting value of the parameter that is set in the parameter setting storage unit;
• a data table on which data in which a size of the machining area and at least one setting value of the parameter influenced by a size of the machining area are associated with each other is registered;
• a machining area determination unit that determines whether data corresponding to a size of the machining area, which is estimated by the machining area estimation unit, is registered on the data table;
• and
• a parameter setting value automatic selection unit that acquires a setting value of the parameter corresponding to a size of the machining area from the data table so as to set the acquired setting value of the parameter in the parameter setting storage unit in a case where the machining area determination unit determines that data corresponding to a size of the machining area is registered on the data table.