PURPOSE: To automate the painting work of a glued edge surface, by providing a guide part for inhibiting the longitudinal movement of a belt to be processed and paint coating sponges mounted through support parts in a free directional manner to enable the painting of both side glued surfaces of the belt.

CONSTITUTION: A sending roller 4 and a traction roller 7 are provided on the upper surface of a machine foundation 1 in opposed relation to each other and the width of the roller 7 is made narrower than that of a belt R to be processed. A first table 11 and a second table 12 are provided before and behind the aforementioned roller 4 and a bridge like part 19 is provided in front of the table 12. In addition, a guide bar part 26 is provided above the bridge like part 19 to prevent the longitudinal movement of the belt 19. Moreover, height changeable pillars are erected at the lateral sides of the bridge like part 19 and a screw rod 30 is traversely spanned to said pillars. A slider is fitted to the screw rod 30 in a slidable manner and a pair of buckets 36' are fixed to said slider. Ink tanks 38' are mounted to said buckets 36' and coating sponges 37 attached to the tanks 38' and brought into contact with the both side glued surfaces of the running belt R.