PURPOSE: To automate the marking work, by arranging marking holes in a ring shape, blowing paint to make marking, and therafter cleaning the part by washing water and a sponge roller.

CONSTITUTION: When a rotary stencil 6 is rotated and the specified marking hole 5 comes directly under an automatic spray gun, water paint is jetted from the spray gun. The pattern of the marking hole 5 of the rotary stencil 6 is painted on the surface of a material to be mrked. At this time, the sponge 14 of a shielding and water sucking head 12 adsorb the oversprayed paint and discharge it from a pipe 15. After the marking of one character has finished, the position of the rotary stencil 6 is calculated and it is turned to the position of a water supply sponge roller 23. As a result the excessive water paint attached to the stencil 6 is washed by a water sucking head 12. Then the position of the next marking hole 5 is calculated by the rotary stencil 6.