An automatic analysis device comprising: a first area with an openable/closable door in a portion thereof, in which a consumable item or a sample to be used for analysis can be supplied from outside the device with the door open; a reaction area located adjacent to the first area in which reaction using the sample is performed; a first opening/closing means for separating the first area and the reaction area in an openable/closable manner; a first air supply means or a first exhaust means for making the reaction area have a higher pressure than the first area; characterized by: a control part for controlling drive of the first air supply means or the first exhaust means according to an open/closed state of the first opening/closing means; a second air supply means or a second exhaust means for making not only the reaction area but also the first area have a higher pressure than outside the device, wherein pressure in the first area is adjusted so as to be lower than in the reaction area; a measuring instrument for measuring an amount of dust in the device; and a display part for displaying an alarm to notify that dust may adhere to the consumable item, according to the measured amount of dust, wherein if the amount of dust measured by the measuring instrument exceeds a predetermined amount, the control part is adapted to drive the air supply means (302, 401) or the exhaust means (303, 402). a first area with an openable/closable door in a portion thereof, in which a consumable item or a sample to be used for analysis can be supplied from outside the device with the door open; a reaction area located adjacent to the first area in which reaction using the sample is performed; a first opening/closing means for separating the first area and the reaction area in an openable/closable manner; a first air supply means or a first exhaust means for making the reaction area have a higher pressure than the first area; characterized by: a control part for controlling drive of the first air supply means or the first exhaust means according to an open/closed state of the first opening/closing means; a second air supply means or a second exhaust means for making not only the reaction area but also the first area have a higher pressure than outside the device, wherein pressure in the first area is adjusted so as to be lower than in the reaction area; a measuring instrument for measuring an amount of dust in the device; and a display part for displaying an alarm to notify that dust may adhere to the consumable item, according to the measured amount of dust, wherein if the amount of dust measured by the measuring instrument exceeds a predetermined amount, the control part is adapted to drive the air supply means (302, 401) or the exhaust means (303, 402). a control part for controlling drive of the first air supply means or the first exhaust means according to an open/closed state of the first opening/closing means; a second air supply means or a second exhaust means for making not only the reaction area but also the first area have a higher pressure than outside the device, wherein pressure in the first area is adjusted so as to be lower than in the reaction area; a measuring instrument for measuring an amount of dust in the device; and a display part for displaying an alarm to notify that dust may adhere to the consumable item, according to the measured amount of dust, wherein if the amount of dust measured by the measuring instrument exceeds a predetermined amount, the control part is adapted to drive the air supply means (302, 401) or the exhaust means (303, 402).