To provide a work posture holding device which can always uniformly pressurize the work on an upper jig plate.

This device is constituted so as to lift a lower jig plate 41 set with the work 3 with an actuator and bring the upper surface 3a of the work 3 into press-contact with the upper jig plate 9. In this case, a plate 37 formed with plural shaft insert holes 39 each having tapered part 39a gradually expanded downward is fitted to an actuator. Plural pieces of shafts 43 each formed with a tapered part 43a engaged with the tapered part 39a at the lower end part are inserted to the lower jig plate 41 while inserting the respective shaft insert holes 39 and also, a coil spring 45 inserted with each shaft 43 is put between the lower jig plate 41 and the plate 37.