A signal of fluorescence emitted from a fluorescent particle of a pathological specimen can be increased in sensitivity and be stabilized, thereby resulting in an enhancement in retrieval accuracy of information from a fluorescence image. A pathological specimen including a tissue section subjected to a treatment (immunostaining/FISH staining treatment) for fluorescence-labeling of an objective biomaterial with a fluorescent particle observable in a dark field, based on an immunostaining or FISH method; a packed layer with which the tissue section is covered; and a protection layer with which the packed layer is covered; wherein
