There is disclosed an electrical signal input device suitable for use in a microwave oven or other household appliance for introducing a setting into those appliances through a simple one-touch actuation. The input device is of the membrane type which includes an actuator member composed of a generally flat plate having a plurality of elongated actuator sections on a surface thereof and carrying a plurality of first electrodes disposed wholly through an opposite surface thereof and facing against the plurality of the actuator sections, a substrate disposed in conjunction with the actuator member and having a plurality of second electrodes each corresponding to one of the first electrode. The first and second electrodes are brought into electrical contact when the corresponding one of the actuator sections is depressed and becomes bent. Discrete values of electrical resistance are sensed as a function of where the first and second electrodes are in electric contact along the length of the actuator sections.