By providing, in an electronic sphygmomanometer, protruding members (505) on the outside perimeter of a first air port connection head (501), when a first air port (327) is pushed into the first air port connection head (501), the protruding members (505) elastically deform going past a first shield plate (323), and are positioned inside the first shield plate (323). As a result, the first air port connection head (501) is prevented from being removed from the first air port (327), and the operator is given a sensation that the device is fitted as the protruding member (505) resumes the original form. Thereby, in the arrangement structure of the pressure sensors used in the electronic sphygmomanometer, the structure around the pressure sensors makes it possible to increase the reliability of blood pressure measurement.