A can inner surface-coating apparatus for coating an inner surface of a bottomed cylinder that becomes a body of a can or a bottle can, comprising: a coating turret, which rotates intermittently and has a plurality of coating pockets arranged at regular intervals in circumferential direction for holding the bottomed cylinder while rotating the bottomed cylinder around an axis of the bottomed cylinder; a spray means (11a-11c), which is placed so as to correspond to a certain position at which the coating pockets stop owing to the intermittent rotation of the coating turret and sprays paint onto the inner surface of the bottomed cylinder held by the coating pocket stopping at that position; an inspection turret, which rotates intermittently and has a plurality of inspection pockets arranged at regular intervals in circumferential direction for holding the bottomed cylinders; an inspection means (13a-13c), which is placed above the spray means (11a-11c) and inspects, at a certain position at which the inspection pocket stops owing to the intermittent rotation of the inspection turret, the bottomed cylinder held by the inspection pocket stopping at that position; a relay means (14a, 14b), which obtains the cylinder coated by the spray means (11a-11c) from the coating pocket and makes the bottomed cylinder be held in the inspection pocket moving toward the inspection means (13a-13c) owing to the intermittent rotation of the inspection turret; characterized by: a cover, which covers a coating area including the spray means (11a-11c) and an inspection area including the inspection means (13a-13c); and an air supply and discharge means, which supplies air from an upper part of the inspection area into an inside of the cover and discharges the air from a lower part of the coating area to an outside of the cover, so as to form air flow moving from the upper part of the inspection area toward the lower part of the coating area, in the inside of the cover. a coating turret, which rotates intermittently and has a plurality of coating pockets arranged at regular intervals in circumferential direction for holding the bottomed cylinder while rotating the bottomed cylinder around an axis of the bottomed cylinder; a spray means (11a-11c), which is placed so as to correspond to a certain position at which the coating pockets stop owing to the intermittent rotation of the coating turret and sprays paint onto the inner surface of the bottomed cylinder held by the coating pocket stopping at that position; an inspection turret, which rotates intermittently and has a plurality of inspection pockets arranged at regular intervals in circumferential direction for holding the bottomed cylinders; an inspection means (13a-13c), which is placed above the spray means (11a-11c) and inspects, at a certain position at which the inspection pocket stops owing to the intermittent rotation of the inspection turret, the bottomed cylinder held by the inspection pocket stopping at that position; a relay means (14a, 14b), which obtains the cylinder coated by the spray means (11a-11c) from the coating pocket and makes the bottomed cylinder be held in the inspection pocket moving toward the inspection means (13a-13c) owing to the intermittent rotation of the inspection turret; characterized by: a cover, which covers a coating area including the spray means (11a-11c) and an inspection area including the inspection means (13a-13c); and an air supply and discharge means, which supplies air from an upper part of the inspection area into an inside of the cover and discharges the air from a lower part of the coating area to an outside of the cover, so as to form air flow moving from the upper part of the inspection area toward the lower part of the coating area, in the inside of the cover. a cover, which covers a coating area including the spray means (11a-11c) and an inspection area including the inspection means (13a-13c); and an air supply and discharge means, which supplies air from an upper part of the inspection area into an inside of the cover and discharges the air from a lower part of the coating area to an outside of the cover, so as to form air flow moving from the upper part of the inspection area toward the lower part of the coating area, in the inside of the cover.