Abstract: A plane, mechanical keyboard comprises several main keys, each of which is surrounded by one or more secondary keys and is mechanically connected to at least one of these secondary keys to define a striking zone. Mechanisms interconnect the main keys and the secondary keys so that each main key, under the effect of a pressure, drives the neighboring secondary keys mechanically connected to this main key downwards and so that a pull-back force exerted on each secondary key exerts a corresponding pull-back force capable of drawing the neighboring main key back upwards when there is no pressure exerted on this neighboring key. This keyboard is designed, inter alia, to be integrated into pocket computer devices or pocket electronic devices or again into portable telephones.