A fine-tuning method of the resonance frequency for a magnetostrictive vibration energy harvester by changing the magnetization state, namely using the ΔE effect of Young’s modulus, is proposed. Adjusting magnetization strength by changing the distance between the magnet for magnetization and the magnetostrictive vibration energy harvester in ten-millimeters revealed to tune the resonance frequency in 0.1 Hz order. A plot of the resonant frequency against the change in the flux density on the magnetostrictive material showed good agreement with a quadratic function approximation. A magnetostrictive vibration energy harvester tuned using this fine-tuning method could generate electricity stably for eleven days, suggesting the possibility of this fine-tuning method for long-term use.