To provide a press fitting device enabling a valve guide and a valve seat to be continuously press-fitted while a workpiece is left as it is.

A movable punch 10 is lowered so that the valve guide 12 set at a mounting shaft 11 is press-fitted into a valve guide mounting hole of a cylinder head W. After the press-fitting of the valve guide 12 by the movable punch 10 is completed, stoppers 9 are each pulled out between a lower surface of a leg part 7 and a base 1 by driving a cylinder unit 8. The movable punch 10 is further lowered, and a cylinder head placing base 4 lowers by an amount allowing the stoppers 9 to come out. The valve seat 14 set at an upper end of a fixed punch 6 is press-fitted to the valve seat mounting part of the cylinder head W.