PURPOSE: To automatically perform the painting of small parts without irregularity, by accurately reproducing prearranged painting work procedure through the orthogonal coordinates type positioning mechanism of a painting gun, a wrist joint mechanism and the rotary mechanism of a turntable.

CONSTITUTION: An orthogonal coordinate type positioning mechanism 3 is provided to the front surface of a painting booth 1 and has degree of freedom in the before-and-behind direction of the painting booth shown by an arrow X, in the lateral direction thereof shown by an arrow Y and the up-and-down direction thereof shown by an arrow Z to guide and locate a painting gun 5 at the arbitrary position on a work space. A mount stand 7 for an object to be painted is provided to the stand 6 of the mechanism at the position below said mechanism 3 and the turntable 9 rotating horizontally to the direction shown by an arrow 8 provided to the upper part thereof has function for revolving a net 11 in a horizontal plane so that the direction of the painting gun 5 is always directed to the booth 1 when the painting article placed on the net 11 is painted.