It is difficult to avoid a decrease in cooling capacity without causing an increase in power consumption if a cooling device including a piping structure grows in size, therefore, a piping structure according to an exemplary aspect of the present invention includes a tubular part including a first flow passage through which a refrigerant flowing and a shell region surrounding the first flow passage; an introduction part composing a part of the shell region and including a second flow passage connected to the first flow passage; and a connection located at an end, between ends of the introduction part, on the side opposite to an end on a side where the second flow passage being connected to the first flow passage.