To provide a carrying roller having stable carrying performance, and to provide a board carrying device.

The board carrying device is used for an in-line type board processing system for performing various kinds of processing while carrying various kinds of boards 3 with the carrying rollers 4. The board carrying device comprises the plurality of carrying rollers 4 arranged at predetermined spaces along a board carrying direction, chambers 60, 62a and 62b partially encircling a plurality of the carrying rollers, a drive mechanism 70 connected to the carrying rollers for transmitting rotation driving forces to the board carrying rollers, and a levelness adjusting mechanism 71 connected to the carrying rollers for adjusting the levelness of the carrying rollers. The levelness adjusting mechanism and the rotation drive mechanism for the carrying rollers are located outside the chambers. The levelness of the carrying rollers is adjusted from the outside of the chambers.