A keyboard apparatus includes: a key; a frame; and a connecting portion configured to connect the key and the frame to each other. The connecting portion includes a flexible member having a rod shape and having flexibility that enables the key to pivot with respect to the frame. The flexible member includes a portion that, in entirety of a range of pivotal movement of the key, maintains a state in which a length of a line extending along a neutral axis of the flexible member between two points located on the neutral axis is greater than a length of a straight line connecting the two points to each other.