A blade inspection apparatus 1 has a borescope 11B and a PC 12. The borescope 11B has a distance sensor 32 for detecting an insertion length L when an insertion section 11a of the borescope 11B is inserted through a hole AP provided in a casing C in which a rotor R of an engine is housed, an acceleration sensor 27 for detecting an attitude of the insertion section 11a, and distance sensors 31a and 31b for detecting two distances from the insertion section 11a to two stator vanes on a stator S. The PC 12 compares the insertion length, attitude and two distances detected in the borescope 11B with the insertion length, attitude and two distances relating to an inspection image stored in a HDD 54. When a match occurs therebetween, the PC 12 outputs match information.