A detection system 1 contains a sensing device 10 including a vibration unit 11 for applying vibration to the inspection target 100, the vibration unit 11 attached to the inspection target 100, a driving circuit 12 for supplying an electric signal to the vibration unit 11 for driving the vibration unit 11 and a sensor 13 for detecting vibration of the inspection target 100 caused by the vibration applied from the vibration unit 11; and a detection processing device 20 for receiving vibration information related to the vibration of the inspection target 100 detected by the sensor 13 from the sensing device 10 and detecting the state change of the inspection target 100 based on the vibration information. The vibration unit 11 includes a coil 112, a spring 113, and a magnet 114b.