In press working, to prevent defects in sheet products and establish the traceability of the causes of defects, we have developed defect detection dies incorporating several types of sensor, including load sensors, fiber laser sensors, ultrasonic sensors and optional sensors. Typical defects such as the rising of pierced scraps, burrs, spring-back/spring-go and wrinkling can be detected using the defect detection dies, i.e., the intelligent forming dies. The real-time defect inspection of all products will be possible. This system can be used to identify defective products on the basis of sensor information compiled in a database. The causes of defects can be clarified from the situation in real time.