To enable even a beginner without sufficient information on a notice of winning in lottery, to positively and immediately recognize a display for the notice when it appears.

At the stop of a reel, three pieces of symbols are displayed in a symbol display window. There are two kinds of symbols which are independent symbols 50 of independent patterns, and partial symbols 51-53 of partial patterns. The partial symbols 51-53 are symbols of 1/3 pattern per piece composed of pattern parts obtained by trisecting one specific pattern. The partial symbols 51-53 are provided in three continuous pieces in a symbol train, and the patterns of the partial symbols 51-53 of three pieces are combined with one another to form one complete pattern. The partial symbol 52 in the central position is set as a prize winning symbol, and the partial symbols 51, 53 in the upper and lower positions are set as failure symbols.