This paper considers nondestructive evaluation techniques for integrity of austenite stainless steel with mechanical fatigue. In order to ensure long time operation of facilities, exact remaining life of each structural component should be predicted by estimating the degree of material degradation including earlier stage before crack initiation. To do it, specimens with several fatigue degrees are prepared which is suitable for nondestructive evaluation. Austenite stainless steel has weak magnetism due to martensite phase induced during processing, whose volume fraction increases according to mechanical fatigue and stress concentration. Magnetic flux leakage testing with high sensitivity can estimate the extent and the distribution of the fatigued region. When we apply a cyclic magnetic field to the specimen, the fatigued region is selectively heated from its magnetic hysteresis, which can be visualized as an infrared image by a thermography. The mechanical fatigue also influences the acoustic properties of the material through the change of the microscopic structure. It is also shown that the acoustic impedance decreases with fatigue. A phased array ultrasonic transducer is developed to obtain the distribution of the acoustic impedance. Feasibility of the proposed techniques is discussed from the view points of qualitative and local estimations.