A cylinder head cleaning method capable of cleaning a cylinder head with an enhanced foreign matter removing rate. The method is used to clean a cylinder head (1) having therein a water jacket (15) including a narrow space portion (Z) having a narrow flow path and a large space (Y) having a flow path wider than the narrow space portion (Z), and the cylinder head (1) further having holes (12A-12R, 13, 14, 16A-16C) communicating with the water jacket (15). Cleaning nozzles (28A, 28C) are inserted into the water jacket (15) from the holes (16A, 16C) selected from the holes (12A-12R, 13, 14, 16A-16C), clearing liquid is ejected from the cleaning nozzles (28A, 28C) toward the narrow space portion (Z), and the cleaning liquid flowing from the narrow space portion (Z) to the large space (Y) is discharged to the outside of the cylinder head (1) from the hole (16B) communicating with the space (Y).