An amplifier selection device includes: a storage that stores a database containing motor models and information pertaining to amplifier capacities and feature amounts; a means that obtains motor model information; a means that calculates a number of amplifiers; a means that selects spindle amplifiers; a means that creates a combination of servo amplifiers and spindle amplifiers; a means that extracts information pertaining to the feature amounts; a means that determines a combination on the basis of the information pertaining to the feature amounts; a power source capacity calculation means that calculates capacities of a main power source and a control power source; a means that calculates a total power consumed by motors; and a display control means that displays the combination of amplifiers and time series data of the total value of the power consumed by the motors along with the main power source and control power source capacities.