Fluorescence observation or fluorescence measuring system, and fluorescence observation or fluorescence measuring method

A fluorescence observation or fluorescence measuring system has at least one of a low-fluorescence objective lens including optical elements made of low-fluorescence glass, satisfying Condition (a) described below, a low-fluorescence immersion substance satisfying Condition (b) described below, and a low-fluorescence cover glass satisfying Condition (c) described below: BOB′/BOB 0.7 (a) BIM′/BIM 0.7 (b) BCG′/BCG 0.7 (c) where BOB′, BIM′, and BCG′ are average intensity values of auto-fluorescence from the low-fluorescence objective lens, immersion substance, and cover glass, respectively, and BOB, BIM, and BCG are average intensity values of auto-fluorescence from a conventional objective lens, immersion substance, and cover glass, respectively, generally used.