A mix distributor (10) for filling a tray-like mold (100) comprises a fixed structure (20), having a distribution surface (24) supporting a mold (100), and a movable housing (30), displaceable above the mold (100) The movable housing is provided with a hopper containing the mix having at its bottom end a port (50) for discharging the mix.An extractor belt (60) which is integral with and positioned underneath the hopper (40), forming the bottom thereof, is able to receive and convey the discharged mi (110) so that it falls by effect of gravity into the mold (100) and is unformly distributed.