A compression bonding device has a dam member so that when a pressing head is pressed against an object to be pressed, the bonding part is surrounded by the dam member. Thus, even if the surface of the bonding part bulges by pressing, the bulging part is stopped by the dam member and the surface of the bonding part does not horizontally extend. As a result of the absence of horizontal extension of the bonding part, electric components of the object to be pressed are not subjected to a force that horizontally moves the electric components and the electric components are vertically pressed downward and connected to the terminals of the substrate. Thus, an electric device having high connection reliability is obtained.