A portable computer includes a monitor, a base, and a hinge. The hinge includes a shaft sleeve, a rotary shaft, a driven element, and a resistance structure. The shaft sleeve is fixed to the base. The rotary shaft is fixed to the monitor and disposed in the shaft sleeve. The driven element is connected to and driven by the rotary shaft. The resistance structure is disposed adjacent to the driven element, wherein the driven element does not contact the resistance structure when the rotary shaft is rotated in a first angular range, and the driven element contacts the resistance structure and sustains a resistance when the rotary shaft is rotated in a second angular range.