A lead frame includes: an outer frame section; a plurality of chip mounting sections which are supported by the outer frame section and on which a plurality of semiconductor chips are mounted; lead sections surrounding the chip mounting sections; connecting sections for connecting and supporting the lead sections and the outer frame section with each other; and an encapsulation region in which the chip mounting sections are encapsulated together in an encapsulation resin. An opening is provided in a plurality of regions of the outer frame section that are each located outside the encapsulation region and along the extension of one of the connecting sections.