In a dynamic flip-flop circuit with a data selection function, for example, when data having an H value is selected using a selection signal, a first node N1 is L, a second node N2 of a second dynamic circuit is H, so that an output signal has an H level. The heat-dissipation unit includes two round hollow casings. The type of chamber which is fabricated is dependent on its intended use. A generating section is configured to generate a pulse signal.