To provide a small power generator adopting a sound insulating panel with a high transmission loss and an excellent sound insulation function, and to provide such sound insulating panel.

The power generator to which the panel 1 is applied includes an engine driving the power generator and a hood having a plurality of panels 1 and housing the engine. The panel 1 is formed by laminating an anterior sound absorbing layer 2 made of a porous and breathable ceramic, a glass wool sound absorbing layer 3, and a concrete sound insulating layer 4 in this order, and placed in the inner surface of the outer panel 120 of the hood with the anterior sound absorbing layer 2 facing to the engine side. Thus, the transmission of machinery sound such as the sound of the engine to the outside is suppressed, and the noise of the power generator can be reduced.