To provide a spring constant variable type magnetic spring device in which the spring constant can be freely varied.

In a magnetic spring using magnetic attractive force as spring force, a mover comprising a permanent magnet and a ferromagnetic body, and at least one stator comprising a coil and a ferromagnetic body are provided. This spring constant variable type magnetic spring device is composed of a magnetic circuit to generate spring force of the magnetic spring by magnetic attractive force of the permanent magnet only, and adjust quantity of flux flowing from the mover comprising the permanent magnet to the stator based on current fed to the coil to vary the spring force of the magnetic spring, a magnetic circuit to change the gap between the mover and the stator to adjust quantity of flux flowing from the mover comprising the permanent magnet to the stator to vary the spring force of the magnetic spring, and a magnetic circuit to replace the permanent magnet by that having different coercive force to vary the spring force of the magnetic spring.