To carry out the load bearing inspection when a press-fit part is press-fitted, to inspect presence or absence of the press-fit parts during the press-fit, and to control the press-fit quantity for each press-fit part.

A press-fit device is provided with a press-fit jig 11 having the weight equal to the required value in a load bearing standard, a holder to hold the press-fit jig 11 in an elevating/lowering manner, and a positioning part 12 to lower the holder 5 from an upper part of a press-fit parts 23 to the position instructed for each kind of the press-fit parts 23 so that the weight of the press-fit jig 11 is applied to the press-fit parts 23. In addition, a detection sensor 16 to judge the presence/absence of the press-fit parts 23 or the sufficiency/insufficiency of the fitting load of the press-fit parts 23 to a pressure- fit receiving parts by lowering the press-fit jig together with the holder 5 through the action of the press-fit jig 11, and a press-fit cylinder 19 to press-fit the press-fit parts 23 into the press-fit receiving parts to the specified position through the press-fit jig 11 by pressing the press-fit jig 11 when the fitting load is judged to be sufficient, are provided. A control device 27 to control the positioning part 12, the detection sensor 16, and the press-fit cylinder 19 is provided.