Disclosed are devices, programs and methods for determining a type of target peptide contained in a test sample, which relate to comparing first to third information on the target peptide obtained from the test sample with first to third information on a known peptide stored in the storage unit; and determining whether or not the target peptide is the known peptide, wherein the first information is a dissociation rate constant when the target peptide dissociates from a protein, in a solid phase carrier in which the target peptide is immobilized on a support through the protein binding to a peptide, the second information is a maximum value of a layer thickness change amount on the support, and the third information is information indicating that a dissociation mode of a peptide and the protein is either a single dissociation mode or a multiple dissociation mode.