A computer mouse with a swingable palm rest cover includes a main body, a switch module, buttons, a magnetic sensor and a magnetic element. The main body has an upper housing and a lower housing. The switch module is disposed in the main body and connected to a circuit board. The buttons are movably disposed on the main body. The palm rest cover is slidably disposed on the upper housing of the main body. The magnetic sensor, which is connected to the circuit board, is disposed on the upper housing or the lower housing. The magnetic element is disposed on the lower housing or the upper housing. When the palm rest cover is swung to left or to right, its displacement can be sensed by the magnetic sensor and the magnetic element, so as to produce a pressure sensing signal and output an analog signal.