A main frame of an IC testing apparatus is formed in the shape of a horizontally elongated box with its height close to the height of wafer probers. Two wafer probers are arranged side by side transversely of the main frame on the front said thereof. One rotary drive is equipped with two output shafts which are connected via respective clutches with the rotary drive, and the testing heads are connected to the associated output shafts. The rotary drive is disposed on the top of the main frame with an extension of the upper portion of the rotary drive, and is adapted to rotatively drive the testing heads connected to the output shifts between a fist position opposing the contact section of the associated wafer prober and a second position over the top of the main frame. This construction reduces the installation areas for each of the wafer probers as well as narrowing the space between the wafer probers and the main frame. |