Abstract: An acoustic-wave measuring device includes: a support table having a support surface configured to support an examination subject, and an opening portion provided in the support surface to measure a predetermined examination site of the examination subject; a container located vertically below the support surface and capable of containing an acoustic matching material in a liquid or gel form; and a receiving element located vertically below the support surface and configured to receive an acoustic wave generated from the examination site, wherein a matching-material bag containing an acoustic matching material in a liquid or gel form or a matching gel having limited flowability and an acoustic control effect, and a placement unit for placement of the matching-material bag or the matching gel thereon are installable between the acoustic matching material contained in the container and the examination site.