Provided is a semiconductor device including a regulator that generates a first voltage and applying the first voltage to a first line; an external terminal that is connected to the first line and externally connects an external component; and a test circuit that inspects a connection state of the external component. The test circuit includes a test discharge execution unit that is configured, upon receiving a test start signal, to stop the operation of the regulator and discharge the external component by connecting the first line to a predetermined potential; and a discharge duration measurement unit that measures a time required from the reception of the test start signal to a drop of the voltage of the first line below a predetermined second voltage, as a discharge duration of the component, and generate discharge duration information about the discharge duration.