A light emitter and a light receiver are provided at a side surface of a lever. When a user grips the lever with his hand, the light emitter and the light receiver are positioned close to bases of the middle finger, a ring finger, and a little finger, as a measurement portion of a palm. A blood-flow blockage reducing component protrudes to contact a portion between the index finger and the middle finger, and a thumb, as a contact portion of the palm.