To provide a power generation device capable of easily and surely adjusting deviation of a resonance frequency even if the resonance frequency deviates from a desired value.

A power generation device 100 comprises: a housing 20; a permanent magnet 31 provided in a displaceable manner along a magnetization direction; a coil 40 separated from the permanent magnet 31 and provided so as to surround an outer peripheral side of the permanent magnet 31; a coil holding part 50 which holds the coil 40 in a relatively displaceable manner with respect to the permanent magnet 31 along the magnetization direction; a pair of leaf springs 60U and 60L comprising a plurality of first spring parts 64 which connect the housing 20 and the coil holding part 50 and a plurality of second spring parts 65 which connect the coil holding part 50 and the permanent magnet 31; and at least one of a first spring constant adjustment mechanism which adjusts a spring constant of the first spring part 64 and a second spring constant adjustment mechanism which adjusts a spring constant of the second spring part 65.