A press forming device for forming a plurality of inwardly directed projections on a circumferential wall of a tubular article to be formed. The press forming device includes a lower die holder adapted to be mounted on a lower base of a press machine, and a die fixed on the lower die holder. The die has a plurality of inside forming parts on a circumferential surface of the die, each for forming one of the projections, respectively. The press forming device further includes a plurality of punches mounted on the lower die holder around an outer circumference of the die, each being arranged to be capable of being moved towards or away from the die, and each having an outside forming part in a position facing one of the inside forming parts for forming one of the projections, respectively. The press forming device also includes an upper die holder adapted to be mounted on an upper raising and lowering base of the press machine and a plurality of pressing members of wedge shape mounted on the upper die holder. Each of the pressing members is mounted at a position above one of the punches for moving one of the punches in a direction towards the die with lowering the raising and lowering base, to thereby press the tubular article between one of the inside forming parts of the die and one of the outside forming parts of the punches, respectively.