A chute for an optical sorting machine allows objects to be sorted to drop under gravity from the lower end of the chute, thereby supplying the objects to an optical detection section. The chute is provided with: a first portion which includes a portion for receiving the objects to be sorted which are supplied from a supply section; and a second portion which continues from the first portion. The first portion is composed of a single part and has: flat surfaces along which the objects to be sorted flow down; and connection surfaces. The flat surfaces located upstream are bent downward and the connection surfaces located downstream are bent upward to form a smooth undulation in the surface along which the objects to be sorted flow down.