Elastic wave device

Provided is an elastic wave device having excellent heat dissipation properties. An elastic wave device (10) is provided with: a support member including a support substrate (14); a piezoelectric layer (16) provided on the support member; and an IDT electrode (11) provided on the first main surface (16a) of the piezoelectric layer (16), an air gap section (14c) opening on the piezoelectric layer (16) side is provided in the support member (14), the support member (14) has an inner wall (14e) facing the air gap section (14c), and the high heat conduction film (17) is directly or indirectly laminated on at least a portion of the second main surface (16b) of the piezoelectric layer (16) and reaches the inner wall (14e) of the support member (14). 本发明提供一种散热性优异的弹性波装置。弹性波装置(10)具备：支承构件，包含支承基板(14)；压电层(16)，设置在支承构件上；以及IDT电极(11)，设置在压电层(16)的第1主面(16a)，在支承构件设置有在压电层(16)侧开口的气隙部(14c)，支承构件(14)具有面向气隙部(14c)的内侧壁(14e)，高热传导膜(17)直接或间接地层叠在压电层(16)的第2主面(16b)的至少一部分，并且到达支承构件(14)的内侧壁(14e)。