To provide a barrel polishing device and a barrel polishing method, capable of reducing the processing time.

The barrel polishing device 10 for polishing a work within a polishing tank 20 containing the work and abrasive grains 40 for polishing the work by causing the abrasive grains 40 to flow within the tank comprises a communication part 22 allowing the inside of the polishing tank to communicate with the outside thereof while preventing leak of the abrasive grains from the polishing tank; and a fluid injection means 50 which injects a fluid into the polishing tank through the communication part to accelerate the abrasive grains in the polishing tank.