To provide a heat storage device of a stirling system capable of being manufactured at a low cost and having a reduced pressure loss.

Protrusions 1a highly precise in specified height and interval are easily formed on a sheet 1b by press-working. After forming the protrusions 1a, the sheet 1b is wound around a tubular cylindrical fixture having a specified diameter and is laminated to easily form the heat storage device having a specified diameter, a specified length and a specified laminated thickness. The heat storage capacity per unit volume can be easily controlled by changing the height of the protrusions 1a.