CRYSTAL RESONATOR

A crystal resonator includes a flat plate-shaped crystal element and excitation electrodes. The crystal element has principal surfaces parallel to an X' axis and a Z' axis. The X' axis is an axis of rotating an X-axis as a crystallographic axis of a crystal in a range of 15 degrees to 25 degrees around a Z-axis as a crystallographic axis of the crystal. The Z' axis is an axis of rotating the Z-axis in a range of 33 degrees to 35 degrees around the X' axis. The excitation electrodes are formed on the respective principal surfaces of the crystal element. The excitation electrodes are each formed into an elliptical shape. The elliptical shape has a long axis extending in a direction in a range of 5 degrees to +15 degrees with respect to a direction that the X' axis extends. 本发明中提供种晶体振子，抑制副振动与主振动的耦合且晶体阻抗值被抑制得低。晶体振子(100b)包括：平板状的晶体片(110b)，具有与X′轴及Z′轴平行的主面，所述X′轴是以作为晶体的结晶轴的Z轴为中心而使作为晶体的结晶轴的X轴在15度至25度的范围内旋转所得，所述Z′轴是以X′轴为中心而使Z轴在33度至35度的范围内旋转所得；以及激振电极(120b)，形成于晶体片的各主面。而且，各激振电极形成为椭圆形形状，椭圆形形状的长轴相对于X′轴延伸的方向而在-5度至+15度的范围的方向上延