Steam engine

The purpose of the present invention is to provide a steam engine having a visual window through which liquid stored in a tank can be easily seen. The steam engine (1) is provided with an outer shell (9) and a tank assembly for storing water, the tank assembly is arranged in the outer shell (9), the outer shell (9) is provided with a visual window (95) along the length direction of the tank assembly, and the amount of water in the tank assembly can be visually confirmed under the condition that water is supplied to the tank assembly and in the process that the steam engine (1) is used. 目的在于提供具备容易目视确认贮存于罐的液体的目视确认窗的蒸汽机。本发明的蒸汽机(1)具备外壳体(9)与贮存水的罐组装体，罐组装体配设于外壳体(9)的内部，在外壳体(9)沿罐组装体的长度方向设有目视确认窗(95)，在向罐组装体供水的情况下与使用蒸汽机(1)的过程中，都能够目视确认罐组装体内的水量。