Elastic wave device and manufacturing method for same

An elastic wave device comprising:

• a support layer including a through-hole or a recess opened at an upper surface thereof;
• a piezoelectric thin film arranged on the support layer to extend above the recess or the through-hole of the support layer;
• and
• an IDT electrode provided on at least one of upper and lower surfaces of the piezoelectric thin film in a region of the piezoelectric thin film that extends above the recess or the through-hole;
• wherein
• a secondary mode of a plate wave, which contains a U1 component as a main component of displacement, is utilized, the piezoelectric thin film is made of LiTaO3, and Euler angles (φ, θ, ψ) of the LiTaO3 fall within specific ranges, where φ is in a range of about 0° to about 30° and θ is in a range of about 0° to about 55° or a range of about 140° to about 180°;
• when θ is in a range of about 0° to about 55°, ψ is in a range of about 180° to about 110°, a range of about 100° to about 50°, or a range of about 40° to about 0°;
• and
• when θ is in a range of about 140° to about 180°, ψ is in a range of about 180° to about 20° or a range of about 10° to about 0°.