Manufacturing method of semiconductor device, method of testing the semiconductor device and wafer holding member

A test method comprising:

• a preparation step of preparing a semiconductor wafer including a small thickness portion including a front surface and the first back surface opposite to the front surface and a large thickness portion surrounding the small thickness portion in plan view, and further including a first electrode formed on the front surface and a second electrode formed on the first back surface;
• a preparation step of preparing a wafer holding member including a wafer placement surface and a second back surface opposite to the wafer placement surface, and having a larger thickness than a difference between a thickness of the large thickness portion and a thickness of the small thickness portion;
• a placement step of placing the semiconductor wafer on the wafer holding member so that the small thickness portion of the semiconductor wafer and the wafer placement surface of the wafer holding member are in contact with each other on the first back surface side of the semiconductor wafer;
• and
• a test step of testing the semiconductor wafer by applying a voltage to the semiconductor wafer through the first electrode, the second electrode and the wafer holding member in a state in which the semiconductor wafer is held on the wafer holding member.