A wire electrical discharge machine (WEDM) including a motion platform, a sink, a workbench, a connecting element, a jib, a first head and a second head is provided. The sink is disposed separately above the motion platform, and the workbench is disposed in the sink. The workbench is connected to the motion platform via the connecting element such that the motion platform drives the workbench moving along a first direction and a second direction. Besides, the jib is fixedly connected with the sink, and the first head is disposed inside the sink and connected with the jib. The second head is disposed above the first head. Thus, the jib does not cause relative motion to the sink in order to avoid leaking.