Abstract: A key-top panel constructed of an electrically non-conductive, resilient material and formed with closed-loop grooves each of which has a closed-loop cross section, each of the closed-loop grooves being deep in the direction of thickness of the key-top panel and having a land portion surrounded by the groove; key-top portions each constituted by the land portion; concavities which are open at the inner face of the key-top panel and which are in registry in cross section with the key-top portions, respectively; and skirt portions each formed between each of the closed-loop grooves and each of the concavities so that the key-top portion surrounded by each closed-loop groove is bridged to an inner wall portion of the key-top panel through each of the skirt portions. The key-top panel may form part of a keyboard structure which may further comprise movable contact elements respectively positioned within the concavities and each fixedly attached to the aforesaid inner end surface portion of each key-top portion.