Disclosed is a testing device. The testing device includes a testing socket configured to support a plurality of probes, a testing-circuit substrate which includes a contact point to contact the probe, a slider which makes the testing socket be coupled to and separated from the testing-circuit substrate, and a slider operator which includes a main body arranged on the testing socket, and a slider pressing portion up/down-movably supported on the main body and moving down from the main body toward the slider so that the slider can slide along a surface direction of the testing socket.