There are provided a biosensor, and a measurement device in which the biosensor is used, with which accurate puncture is enabled and reliability of measurement results are improved. The biosensor (4) comprises an element substrate (9), a detector (10), a connection terminal (11), a continuity path (12), and a cutout (13). The detector (10) is provided over the element substrate (9), and receives a specimen and detects a specific component contained in the specimen. The connection terminal (11) is provided over the element substrate (9) and acquires current corresponding to the specific component. The continuity path (12) connects the connection terminal (11) and the detector (10). The cutout (13) is formed along the outer periphery of the detector (10) so as to surround two or more directions of the detector (10).