Surface acoustic wave resonator, surface acoustic wave oscillator, and electronic instrument

A surface acoustic wave resonator provided on a quartz crystal substrate with Euler angles (−1.5°≦φ≦1.5°, 117°≦θ≦142°, and 42.79°≦|Ψ|≦49.57°, comprising:

• an IDT which excites a stop band upper end mode surface acoustic wave;
• and
• inter-electrode finger grooves hollowed out of the substrate positioned between electrode fingers configuring the IDT, wherein
• when the wavelength of the surface acoustic wave is λ and the depth of the inter-electrode finger grooves is G, λ and G satisfy the relationship of
• 0.01λ≦G
• and wherein,
• when the line occupation rate of the IDT is η, the inter-electrode finger groove depth G and line occupation rate η satisfy the relationships of
• −2.0000×G/λ+0.7200≦η≦−−2.5000×G/λ+0.7775
• provided that
• 0.0100λ≦G≦0.0500λ
• −3.5898×G/λ+0.7995≦η≦−2.5000×G/λ+0.7775
• provided that
• 0.0500λ<G≦0.0695.