To provide a window frame for a pinball game machine in which a multiple-layer transparent plate is attached to a window frame body through one action simply and speedily with an excellent workability, and which can prevent the accident of erroneously dropping and breaking the multiple-layer transparent plate.

The window frame of the Pachinko game machine comprises the window frame body 17 covering the front surface of a game board 5, where a window 19 to which the game part 5a of the game board 5 faces is opened, and the multiple-layer transparent plate 18 attached to the back surface of the window frame body 17 for closing the window 19 by a transparent plate 28. An engaging part 23 is provided on one of the back surface upper part of the window frame body 17 and the front surface upper part of the multiple-layer transparent plate 18, and a part 33 to be engaged with the engaging part 23 so as to be freely engaged and disengaged is provided on the other. Also, a holding part 24 for holding the lower edge part of the multiple-layer transparent plate 18 is provided on the back surface lower part of the window frame body 17.