A soundboard, which vibrates and generates tones, does not hit the mounting member (components); as a result abnormal vibration/noise is not caused; a contact members are contacted and attached on the both sides of the soundboard which generates tones; the contact member is softer than the soundboard; mounting member is harder than the contact members, mounting members are contacted outside the both contact members; all of them from the mounting members through the mounting members are held and fixed with the connect members; the soundboard is detached from the hard mounting members with the soft contact member (sheet) in between; therefore the tone characteristics of the soundboard do not deteriorate, and abnormal vibration/noise caused by resonance of soundboard and other components do not occur.