A sputum apparatus includes a suction line, a switching unit, a measurement unit, and a control unit. The suction line has a suction inlet which aspirates sputum produced in patients respiratory tract and an accommodating part maintained at negative pressure, which accommodates the aspirated sputum. The switching unit is in the suction line, and can switch between first state where the suction inlet communicates with the accommodating part, and second state where the suction inlet is shutoff from the accommodating part. The measurement unit measures the expired air being aspirated into the accommodating part, under the first state. The control unit can switch the switching unit from the second state to the first state during expiration, and keep the first state when the expired air measured by the measurement unit is under predetermined value.
