1. A machining condition selecting device for a machine tool, comprising:a processor configured to perform the processes of:
managing machining condition contribution data in which each of a plurality of machining conditions that a machine tool can perform when machining a target product is associated with degrees of contribution to each item of a 3-dimensional surface roughness parameter of a cutting surface of the target product and degrees of contribution to each item of a required condition related to productivity of the target product;
acquiring a combination of at least one item of the 3-dimensional surface roughness parameter and at least one item of the required condition as a matter of priority specified by an operator;
managing, for each of the plurality of machining conditions, machining condition selection data in which a combination pattern of items that can be specified as the matter of priority is associated with a sum of the degrees of contribution to each item in the combination pattern;
selecting a machining condition on the basis of the sum of the degrees of contribution associated with the combination pattern of the machining condition selection data matching the combination of the matters of priority;
acquiring actual measurement values and target values of each item of the 3-dimensional surface roughness parameter of the cutting surface of the target product as a target surface; and
outputting each item of the 3-dimensional surface roughness parameter of the target surface having an actual measurement value that is different from the target value.