MEMS resonant sensing devices require both HF (f) and low dissipation or high quality factor (Q) to ensure high sensitivity and high speed. In this study, we investigate the resonance properties and energy loss in the first three resonance modes, resulting in a significant increase in f‧Qproduct at higher orders. The third order resonance exhibits an approximately 15-fold increase in f‧Qproduct, while the Qfactor remains nearly constant. Consequently, we achieved an ultrahigh f‧Qproduct exceeding 1012Hz by higher-order resonances in single-crystal diamond cantilevers.