Even when a large-current, high-voltage load is applied, damage is prevented. A current generating device (1) supplies a current simulating a current flowing when lightning occurs to a test piece (9) subjected to a lightning resistance test using power supplied from a power supply device (2). The current generating device (1) includes electric double-layer capacitors that store and discharge power supplied from the power supply device (2), a semiconductor switch (3) that switches between supplying and not supplying the power stored in the electric double-layer capacitors to the test piece (9), and a protection unit (4) that is connected between the semiconductor switch (3) and the test piece (9) and that cuts the connection between the semiconductor switch (3) and the test piece (9) when a current larger than a predetermined value flows through the semiconductor switch (3).