A method for manufacturing a bonded wafer, the method including bonding a to-be-bonded wafer and a compound semiconductor wafer including a compound semiconductor epitaxially grown on a growth substrate. An area of a bonding surface of the to-be-bonded wafer is larger than an area of a bonding surface of the compound semiconductor wafer. The growth substrate is removed after the to-be-bonded wafer is bonded to the compound semiconductor wafer.