To improve setting property of a rim and a disk and to keep optimal press fitting depth accuracy (positioning accuracy) by avoiding floating when the disk is pressed into the rim.

This press fitting device comprises clamp arms 50a and 50b for fixing the disk D set in a top force section 24, and a clamp member 106 for fixing the rim R set along a supporting surface of a bottom force section 28. The device comprises an abutting member 62 and a butted member 60 used for setting a press fitting depth of the disk D into the rim R by abutting when the top force section 24 is lifted down under a driven operation of a first cylinder 20 and the disk D fixed to the top force section 24 is pressed into an opening of the rim R fixed to the bottom force section 28.