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 comprises an element substrate, a detector, a connection terminal, a continuity path, and a cutout. The detector is provided over the element substrate, and receives a specimen and detects a specific component contained in the specimen. The connection terminal is provided over the element substrate and acquires current corresponding to the specific component. The continuity path connects the connection terminal and the detector. The cutout is formed along the outer periphery of the detector so as to surround two or more directions of the detector.