A key structure includes a support shaft, a resilience sheet, a pedestal and a keycap. While the keycap is pressed down in response to an external force, the support shaft is moved downwardly and the resilience sheet is correspondingly moved. Since a resilience part of the resilience sheet is pushed by a push part of the pedestal, the resilience part is subjected to deformation. After the resilience part is moved across the push part, the resilience part is elastically restored and swung. Consequently, the resilience part collides with the inner surface of the sliding groove to generate a click sound.