An acoustic device includes a main body case, a vibrating body provided inside of the main body case, a magnetic circuit unit disposed in front of the vibrating body in a sound emitting direction of the vibrating body, a coil located inside of a magnetic gap of the magnetic circuit unit, a bobbin configured to support the coil and vibrate along with the vibrating body, and a damper configured to connect the main body case to the bobbin. The damper is disposed in the rear of the vibrating body, and a damper regulation unit is provided in the rear of the damper at a position facing the damper.