an ic tester having a plurality of tester pins to be connected to input terminals and output terminals of ics to be tested comnprises : a common timing generator for generating a common timing which is common to all the tester pins ; a dedicated timing generator for generating dedicated timings which are independent of each other and respectively dedicated to tester pin units , each of the tester pin units being composed of at least two of the plurality of tester pins ; and a setting device for setting the respective dedicated timings generated by the dedicated timing generator to the tester pins of the corresponding tester pin units , the other tester pins selecting the common timing generated by the common timing generator .