To provide a pachinko machine and its prize winning control method that can prevent the pleasure of a game from being spoiled and enhance the player's feeling of expectation while balancing a player's profit and a game provider's loss.

A CPU 112 of a main control device 105 of this pachinko game machine 1 determines whether to replace the functions of a left starting prize port 34 and a middle starting prize port 33 on the basis of a signal from a specific prize port 31 of a generator prize winning device 30. In the case the determination results in replacing the functions, after the production of a specific game state based on a prize winning entry into the specific prize port 31, the functions of both ports are replaced to produce a special starting port game state.