To provide ground-fault circuit interrupter, in which an arrangement of a test terminal unit is not limited and various parts constituting it can be arranged freely, and which is small in size and has low profile.

The test button 2 is formed bent into a nearly crank-shape. One end of the test button 2 projects from an upper surface of a breaker case 5, and a pivotal shaft 6 is provided at a vicinity of the bent portion near the other end, whereby the test button is born to the breaker case 5. The test button 2, if pushed, pivots around the pivotal shaft 6 and pressurizes the test spring 3 with the other end energized in a nearly horizontal direction toward a test spring 3. The test spring 3 is curved to make contact with a tip of a test terminal 4, a test circuit is closed, and a dummy leakage current flows, whereby the action of a ground-fault circuit interrupter 1 can be confirmed. Various parts can be arranged in a space formed underneath the test button 2.