An optical sensor device has an optical semiconductor element fixed into a recessed portion of a base portion, and a pad portion of the optical semiconductor element is electrically connected to a lead portion of the base portion. On an upper surface of a protruding portion provided in an outer region of the base portion, a metallization layer having notch portions, a metal bonding layer, a metallization layer having notch portions, and a lid portion are provided. Through use of the metallization layers and the metal bonding layer, the lid portion can be hermetically bonded to the base portion.