A keyboard apparatus includes a plurality of keys, a frame supporting the plurality of keys arranged in a first direction, a first member, a longitudinal direction of the first member being along the first direction, and a second member including a first section, a second section, and a third section, the first section, the third section, and the second section being arranged in this order in a second direction perpendicular to the first direction, the first section being a plate-shaped member sandwiched between the first member and the frame, the second section being connected to the first member at a position away from the first section, the third section being separated from the first member between the first section and the second section, and a longitudinal direction of the second member being along the first direction.