The present invention provides a chemical solution that, in a case where the chemical solution is applied to a processing target containing SiGe and an Si-containing material other than SiGe, has a high etching rate ratio of SiGe to the Si-containing material and leaves little residue on the Si-containing material after application. The present invention also provides a method for processing a processing target and a method for producing a semiconductor device. The chemical solution according to an embodiment of the present invention is a chemical solution that is used for a processing target containing SiGe and an Si-containing material other than SiGe and that removes at least a part of the SiGe contained in the processing target. The chemical solution contains a polymer including a first repeating unit having at least one group selected from the group consisting of a primary amino group or a salt thereof, a secondary amino group or a salt thereof, a tertiary amino group or a salt thereof, and a quaternary ammonium group, and a second repeating unit selected from the group consisting of a repeating unit having an acid group and a repeating unit represented by —SO2—, a fluoride ion source, and an oxidizing agent.