A semiconductor device (1) according to the present invention includes a circuit to be tested (2) having a scan chain, and a first test control device (3) and a second test control device (4) that perform a scan test of the circuit to be tested by using the scan chain. The second test control device (4) performs a second scan test of the circuit to be tested (2), the circuit to be tested (2) gives the first test control device (3) an instruction to perform a first scan test after the second scan test is performed, and the first test control device (3) performs a first scan test of the circuit to be tested (2) in response to an instruction from the circuit to be tested (2).