PURPOSE: To enhance detection capacity and resolving power in the inspection in the bonding state of a surface panel and a panel core while making it possible to automate inspection, by vibrating the surface panel by generating an eddy current in such a state that a magnetic field is applied to the surface panel, and detecting the change in the vibration frequency, amplitude and attenuation thereof.

CONSTITUTION: If the bonding state of a surface panel 16 and a panel core 17 are well, the surface panel 16 has constant inherent vibration frequency corresponding to the thickness or quality thereof. Therefore, a vibration sensor 11 is constituted of a permanent magnet 14 and a coil 15 while an alternating current is flowed to the coil 15 to generate an eddy current in the surface panel 16 and vibration corresponding to the frequency of the alternating current can be generated in the face panel 16. By this method, inherent vibration frequency is generated in the face panel 16 and this vibration state is detected as the change in the impedance of the coil 15. The bonding inferior position of a honeycomb panel 10 is detected by a position sensor 12 and displayed by CTR20 or recorded by a printer 21.