PURPOSE: To obtain a follower apparatus good in following property and reduced in a flaw detection impossible region, by moving or rotating three moving bodies by bringing the same into contact with plural flaw detection heads and holding the flaw detection heads to the same position to a material to be insepcted.

CONSTITUTION: A material 2 to be inspected is conveyed from a direction shown by the arrow and sent into an ultrasonic flaw detection apparatus through pinch rollers 4a, 4b. When the material 2 to be inspected has a curve or a twist, it is contacted with a conical guide 29. The guide 29 is fixed to a third moving body 28 and moves so as to follow the curve or twist of the material 2 to be inspected along with the advance of the material 2 to be inspected through a second moving body 26, a first moving body 12, a rolling mechanism 25, a slider 27 moving to a Y-direction and a slider 13 moving to an X-direction. When the leading end of the material 2 to be inspected passes a flaw detection head 19, an actuator 18 is operated and the flaw detection heat 19 rises to a predetermined position. Similarly, a second flaw detection head is contacted with the material 2 to be inspected and both heads certainly follow the material to be inspected.