ENERGY CONVERSION DEVICE

PROBLEM TO BE SOLVED: To provide an energy conversion device capable of increasing the energy conversion efficiency.SOLUTION: An energy conversion device 1 includes: a magnet block 3 having plural magnets 2; and a coil block 4 having plural coils 4a. The magnet block 3 and the coil block 4 are disposed being faced each other. When the magnet block 3 and the coil block 4 make a relative movement in a predetermined direction perpendicular to a facing direction, an electromagnetic induction is generated; thus a function to convert a kinetic energy into an electrical energy is achieved. The energy conversion device 1 includes: a movable part 12 including the magnet block 3; a support part 14; a first spring 15 interposed between the movable part 12 and the support part 14; and a second spring 16 interposed between the movable part 12 and the support part 14. The first spring 15 is constituted of a compression coil spring. The spring constant of the second spring 16 in a predetermined direction is smaller than the spring constant of the first spring 15, and the spring constant in the predetermined direction is smaller than the spring constant in a direction perpendicular to the predetermined direction.