Disclosed is a data entry keyboard which has a multitude of depressible keys which are selectively depressed for the entry of predetermined data. In the keyboard, an insulating member is sandwiched between a first substrate having stationary electrodes and a flexible second substrate having movable electrodes. The stationary and movable electrodes face one another through apertures formed in the insulating member. Upper and lower marginal surface portions of the insulating member, including the respective peripheral edges of the apertures, are kept parallel to the first and second substrates corresponding thereto by a plurality of protuberances on the substrates so that voids with a predetermined width are left between the marginal surface portions and the individual substrates. The movable electrodes of the second substrate are electrically fixed, in the form of a cantilever each, to the extreme end portions of branch conductor strips which diverge from a main conductor strip at right angles thereto. When one of the keys is depressed, the second substrate is deformed to narrow the corresponding void, thus bringing the corresponding movable and stationary electrodes into contact with each other.