The invention provides a disinfecting device. In a bottle housing a concentrated disinfecting liquid, an mouth is sealed with an obstruction portion. An opening portion of the bottle can enable the obstruction portion to be broken in the way that a part of the upper part of the obstruction portion is taken as a connecting portion to be reserved, and bends the obstruction portion from the connecting portion to the inner part of the bottle, thereby forming an outlet of the concentrated solution. After discharging the concentrated solution, the cleaning fluid from a nozzle is used for cleaning the inner part of the bottle. The nozzle is arranged at the position where the cleaning fluid and the obstruction portion are not collided and at the position above the water level of a returned cleaning fluid. The opening portion of the bottle has a blade portion for forming a cut on the obstruction portion. The concentrated solution from the cut is discharged by a liquid-discharging passage way formed on the external surface of the opening portion of the bottle.
