A power spring mechanism and equipment having the mechanism, wherein a core (10) is connected to the inner end (11a) of a power spring (11) and the outer end (11b) of the power spring (11) is connected to a barrel drum (12), a braking plate (15) is disposed inside a braking case (14) and fluid substance (16) is filled in the braking case, a recess and projection connection part (10b) is provided at the bottom of the core (10) and engaged with the recess and projection connection part (15b) of the braking plate (15) disposed in the braking case (14), whereby, by simplifying the structure of the power spring mechanism having the braking means and adopting the structure allowing the number of parts to be reduced, the size and production cost of the power spring mechanism can be reduced.