Tunnel-type machine to wash objects comprising a containing structure which internally delimits a single work volume and which is provided with at least an entrance door to feed the objects in a loading direction, wherein the work volume comprises: at least two processing chambers (22, 23) contiguous in the loading direction, a single separation door provided between said two processing chambers (22, 23), which separation door is configured mobile through a passage aperture of the containing structure, along a movement plane between an open position outside the work volume and a closed position inside the work volume in order to separate the two chambers (22, 23), said passage aperture lying on a lying plane which is transverse with respect to the movement plane of said separation door, characterized in that said machine comprises: at least a front packing between the two processing chambers (22, 23), positioned inside said containing structure, along at least the greater part of the perimeter of the cross section of the containing structure, and lying on a sealing plane parallel to said movement plane, at least an upper packing at the passage aperture, said separation door being configured to contact, in the closed position, both the front packing and the upper packing, movement means being provided, configured to move the separation door from the movement plane toward said sealing plane in the loading direction, to determine the passage of said separation door from the closed position to a further sealing position, in which said separation door is in contact not only with said upper packing but also with said first front packing and exerts on the latter a compression thrust in order to obtain the seal. at least two processing chambers (22, 23) contiguous in the loading direction, a single separation door provided between said two processing chambers (22, 23), which separation door is configured mobile through a passage aperture of the containing structure, along a movement plane between an open position outside the work volume and a closed position inside the work volume in order to separate the two chambers (22, 23), said passage aperture lying on a lying plane which is transverse with respect to the movement plane of said separation door, characterized in that said machine comprises: at least a front packing between the two processing chambers (22, 23), positioned inside said containing structure, along at least the greater part of the perimeter of the cross section of the containing structure, and lying on a sealing plane parallel to said movement plane, at least an upper packing at the passage aperture, said separation door being configured to contact, in the closed position, both the front packing and the upper packing, movement means being provided, configured to move the separation door from the movement plane toward said sealing plane in the loading direction, to determine the passage of said separation door from the closed position to a further sealing position, in which said separation door is in contact not only with said upper packing but also with said first front packing and exerts on the latter a compression thrust in order to obtain the seal. at least a front packing between the two processing chambers (22, 23), positioned inside said containing structure, along at least the greater part of the perimeter of the cross section of the containing structure, and lying on a sealing plane parallel to said movement plane, at least an upper packing at the passage aperture, said separation door being configured to contact, in the closed position, both the front packing and the upper packing, movement means being provided, configured to move the separation door from the movement plane toward said sealing plane in the loading direction, to determine the passage of said separation door from the closed position to a further sealing position, in which said separation door is in contact not only with said upper packing but also with said first front packing and exerts on the latter a compression thrust in order to obtain the seal.