A surgical apparatus particularly suited for sequentially applying a plurality of fasteners to body tissue and simultaneously incising tissue is provided. A handle assembly includes a movable handle. The movable handle is movable through an actuation stroke. An elongate body extends distally from the handle assembly and defines a longitudinal axis. The elongate body has a distal end adapted to releasably engage both articulating and non-articulating disposable loading unit types. An actuation shaft is supported at least in part within the handle assembly and is mounted for longitudinal movement in response to manipulation of the actuation handle. An energy activated firing lockout system prevents operation of the surgical apparatus under a plurality of conditions.
