PURPOSE: To enable an eddy current flaw detection test even through a film, by measuring the thickness of the film on the surface of a metal and adjusting the sensitivity and phase of an eddy current flaw detector on the basis of the measured value.

CONSTITUTION: An eddy current flaw detection apparatus consists of a truck 11 moving along the film 10 on the surface of a metal, the eddy current flaw detection sensor 12 mounted to the truck 11, an eddy current flaw detector 13 for performing eddy current flaw detection on the basis of the output of said sensor 12, the film thickness measuring sensor 14 mounted to the truck 11 and an adjusting device 15 for setting the sensitivity and phase of the eddy current flaw detector 13 on the basis of the output of said sensor 14. When the flaw detection test of the metal surface is performed, the angle and position of a sleigh 31 are adjusted so as to contact the sleigh 31 with the surface of the film 10 under proper pressure. When the truck 11 is moved, the thickness of the film 10 is measured by the sensor 14 and the adjusting device 15 sets the sensitivity and phase of the eddy current flaw detector 13 on the basis of the output of the sensor 14 and the eddy current flaw detector 13 processes the output of the sensor 12 and the result is outputted to a cathode ray tube and a recorder 32.