Method for manufacturing soi wafer

A method for manufacturing an SOI wafer comprising a step of performing an adjustment to a film thickness of an SOI layer of the SOI wafer by wet etching,

• wherein in the step of performing the adjustment to the film thickness of the SOI layer:
• a first etching step of etching a surface of the SOI layer using an SC1 solution;
• and
• a second etching step of etching the surface of the SOI layer by bringing the SOI layer into contact with ozone water to form an oxide film on the surface of the SOI layer and then bringing the formed oxide film into contact with an HF-containing aqueous solution to remove the oxide film,
• are performed in combination, and
• the etchings in the first etching step and the second etching step are performed such that a removal amount of the SOI layer in the first etching step is smaller than a removal amount of the SOI layer in the second etching step.