To install a Pachinko machine on a Pachinko island so that the upper part of a mounting frame of the Pachinko machine can be mounted without looseness or rattling even when the type of the mounting frame differs.

The apparatus for mounting an upper part of the mounting frame of a Pachinko machine is so configured to hold the mounting frame by detachable arm plates of spring members to be mounted on a base material fixed on a Pachinko island while using the front edge of the mounting frame as a reference position for mounting. Even if there is an obstacle when mounted at the front edge of the mounting frame, the mounting positions of the arm plates can be shifted.