An indoor unit for an air-conditioning apparatus includes a casing forming an outer frame. The casing includes a lower right-side panel, a right bottom panel, a lower left-side panel, and a left bottom panel. The lower right-side panel, the right bottom panel, the lower left-side panel, and the left bottom panel each include a panel provided with a void through which pipes are drawn out and a panel without the void. The lower right-side panel, the right bottom panel, the lower left-side panel, and the left bottom panel with or without the void are selectively attached to the indoor unit.