Abstract: The present invention relates to a method of producing a protein for which two or more characteristics are optimized simultaneously. More specifically, the present invention relates to a method of producing a protein for which two or more characteristics are optimized, the method comprising: 1) providing a library comprising mutants from random mutation of a target protein; 2) determining respective characteristic values that indicate the two or more characteristics of some of the mutants in the library, and scoring the two or more characteristic values as one value per mutant by normalizing and integrating the characteristic values; 3) conducting machine learning by using the score values and ranking the library; and 4) selecting a protein for which two or more characteristics are optimized, based on the ranking results, wherein the two or more characteristic values are numerical values based on different measurement data related to respective different characteristics.