PURPOSE: To attain miniaturization and to enhance the strength against impact, by cutting a bending mode AlPO4 vibrator at an angle rotating a Z-plate by 30W60° around an X-axis being a rotary axis.

CONSTITUTION: Both end parts 3 of an AlPO4 vibrator 1 are fixed to a support stand 2 made of an insulating material by an adhesive 4 and the stress sensitivity to the application of stress by the change in temp. generated by the fixation of both end parts of said vibrator 1 is made small. Therefore, the frequency of fundamental wave vibration when load acts on both ends of the vibrator 1 is calculated theoretically and a cut angle for increasing Young modulus is theroretically calculated on the basis of said frequency to calculate an angle of 30W 60° which is, in turn, used.