To provide a technique for miniaturizing a spring unit having a damper for decelerating the extension speed of a spring.

The spring unit 30 includes a coil spring 38, a first cylindrical member 31 and a second cylindrical member 46. The first cylindrical member 31 has a first spring seat 32 abutting on the upper end of the coil spring 38, a first cylindrical stroke 36 extending in the extension direction of the coil spring 38 along inside the coil spring 38 from the first spring seat 32, and an absorber 40 fixed to the first cylindrical stroke 36. The second cylindrical member 46 has a second spring seat 48 abutting on the lower end of the coil spring 38, a second stroke 42 extending in the extension direction of the coil spring 38 along inside the coil spring 38 from a second spring seat 48 to reach the first spring seat 32 side further than the absorber 40, and an abutting member 44 fixed to the first spring seat 32 side further than the absorber 40. The axial center 38a of the coil spring 38 satisfies the positional relationship passing through the abutting member 44 and the absorber 40.