1. An applicable patch selection device, comprising: a first extraction unit for extracting, on the basis of information on an application target system, information on all the patches unapplied to the application target system from among information on released patches; an input unit to which a user's policy is input; a second extraction unit for extracting, in accordance with the user's policy input into the input unit, information on an unapplied patch to be actually applied to the application target system from among the information on all the unapplied patches extracted by the first extraction unit; and an unapplied patch obtainment unit for obtaining an unapplied patch corresponding to the information, extracted by the second extraction unit, on the unapplied patch to be actually applied to the application target system.