A key structure includes a key, a key sheet and a supporting portion. The key displaces in a direction. The key sheet is disposed at a side of the key toward which the key displaces and comprises a sheet base portion and a contacting portion that displaces in the displacing direction of the key in accordance with a displacement of the key. The supporting portion is disposed between the key and the sheet base portion and supports one end portion of the key by contacting a member disposed opposite to the supporting portion while the other end portion of the key displaces in the displacing direction of the key.