It is possible to accurately judge whether the amount of coolant filled in a multi-type air conditioner is appropriate even when the amounts of the coolant filled at site are irregular or even when the reference value of the operation state amount used for judging whether the coolant amount is appropriate fluctuates by difference in the coolant piping length, combination of the used units, or the installation height between units. The coolant amount judgment system judges whether a coolant amount is appropriate in an air conditioner (1) having a coolant circuit (10) formed by a heat source unit (2) and use units (4, 5) connected by coolant piping (6, 7). The system includes state amount accumulation means and coolant amount judgment means. The state amount accumulation means accumulates the operation state amount of the coolant flowing in the coolant circuit (10) filled with coolant of the initial coolant amount by the coolant filling at site or components. The coolant amount judgment means compares the current value of the operation state amount to a reference value of the operation state amount obtained at the test operation and judges whether the coolant amount is appropriate.
