Sonic wave sensor unit, and recording device

A sonic wave sensor unit, comprising:

• a sonic wave sensor including
• an element substrate having a transmitting element having a transmission side piezoelectric element and a transmission side vibrating surface coupled to the transmission side piezoelectric element and configured to transmit a sonic wave to a target, and a receiving element having a reception side piezoelectric element and a reception side vibrating surface coupled to the reception side piezoelectric element and configured to receive a sonic wave reflected by the target and
• a sealing substrate facing the element substrate, and configured to seal the transmission side piezoelectric element and the reception side piezoelectric element;
• and
• a holder disposed on a side opposite to the element substrate with respect to the sealing substrate, in a first direction from the sealing substrate toward the element substrate, the holder being fixed to the sealing substrate, wherein
• a hole is formed in the holder, the hole extending through the holder in the first direction, and
• in plan view viewed in the first direction, the reception side vibrating surface is disposed inside a wall surface of the holder constituting the hole.