To provide a disk supporting apparatus, a disk holding apparatus and a disk apparatus whose planar dimension is minimized, and which can be manufactured simply and inexpensively.A plurality of supporting portions 44 inclines with respect to a top portion 46 as a vertex. A tray 26 is formed into a substantially triangular pyramid (three-dimensional) configuration, and a planar dimension of the tray 26 can be smaller than that of a conventional turntable. Accordingly, a plurality of disks can be mounted on the tray 26. The supporting portion 44 of the tray 26 can be placed in parallel to a door leaf without a slide mechanism that has conventionally been used for sliding a tray. Accordingly, a desired disk can be attached/detached merely by rotating and driving the tray 26, and a mechanism disposed at a stereo apparatus is made compact and manufactured inexpensively.