A test system of embodiments electrically connects one or more first semiconductor chips formed on a first wafer and one or more second semiconductor chips formed on a second wafer to perform tests on the one or more first and second semiconductor chips. The test system includes a test device that supplies a test signal to each of the one or more first semiconductor chips, a first probe device including a first probe to be connected to a first internal pad of each of the one or more first semiconductor chips and a first communication circuit configured to transmit and receive a signal, and a second probe device including a second probe to be connected to a second internal pad of each of the one or more second semiconductor chips and a second communication circuit configured to transmit and receive the signal to and from the first communication circuit.