This paper introduces an insect-mimicking flapping-wing system, where wing rotation, wing corrugation, and wing clap of real insects have been mimicked. The flapping system is actuated by a unimorph piezoceramic actuator unlike most motor-driven flapping systems. The artificial wing is made of a thin polyethylene sheet and the wing corrugation is implemented afterward. Since the wing is assembled through a pitching hinge, the wing can passively rotate about the hinge during the flapping motion due to the resultant aerodynamic force. Effects of wing rotation, wing corrugation, and wing clap have been experimentally explored by measuring the vertical force produced by the flapping systems. By using the smoke-wire flow visualization technique, it has been confirmed that the flapping wing system can generate the leading and trailing edge vortices, which are essential for the lift and thrust generation in the insect flight.