To push in a brush holding member 9 into a working hole 7 of a table base 5 with small push in force and not to cut a corner part of a locking part 17 when pushing in the brush holding member 9.

Many working holes 7 are formed to a table base 5, brush holding members 9 to plant/hold brush bundles 3 to respective working holes 7 are respectively arranged freely mounting/dismounting, respective brush holding members 9 are respectively with a fitting part 13 fitted to a holding hole 11 and the working hole 7, a part 15 supported to one end of the working hole 7 and a lock part 17 locked to the other end of the working hole 7, slits 21 encircling the locking part 17 with a connecting part 19 are formed to respective brush holding members 9, the locking part at respective holding member is respectively constituted so as to be elastically deformable in the direction approaching/separating for the center of the holding hole 11 while taking the connecting part 19 for a reference.