A sensing device for a non-volatile memory includes a reference circuit, two switches, a sensing circuit and a judging circuit. The reference circuit is connected to a first node. A first terminal of the first switch is connected with the first node and a control terminal of the first switch receives an inverted reset pulse. A first terminal of the second switch is connected with the first node, a second terminal of the second switch receives a ground voltage, and a control terminal of the second switch receives a reset pulse. The sensing circuit is connected between the second terminal of the first switch and a second node. The sensing circuit generates a first sensed current. The judging circuit is connected to the second node. The judging circuit receives the first sensed current and generates an output data according to the first sensed current.