A microscope imaging system (1A, 1B) comprising: a stage having a mount face on which a specimen is to be mounted; an imaging unit having an imaging element for imaging a part of an imaging region set on the mount face; and an imaging optical unit arranged between the stage and the imaging unit and having an objective lens for imaging light from the part of the imaging region onto the imaging unit, wherein the stage is arranged so that the mount face is orthogonal to an optical axis (L, L1) of the objective lens, and wherein the stage is configured to be movable in a first direction obliquely intersecting with the optical axis (L, L1) while the mount face is kept orthogonal to the optical axis (L, L1), a moving mechanism for moving the stage in the first direction obliquely intersecting with the optical axis (L, L1) and a second direction orthogonal to the first direction, a focus adjustment driving mechanism for moving the objective lens in a direction along the optical axis (L, L1), and characterized by the system (1A, 1B) further comprising a control unit configured to control, during a microscope imaging method, the moving mechanism to move the stage in the first direction and in the second direction, and to control, during the microscope imaging method, the focus adjustment driving mechanism so as to adjust a focus of the objective lens on the specimen in correspondence to the movement of the stage in the first direction, wherein, for adjusting the focus of the objective lens on the specimen, a moving direction of the objective lens is limited to the one direction along the optical axis (L, L1). a stage having a mount face on which a specimen is to be mounted; an imaging unit having an imaging element for imaging a part of an imaging region set on the mount face; and an imaging optical unit arranged between the stage and the imaging unit and having an objective lens for imaging light from the part of the imaging region onto the imaging unit, wherein the stage is arranged so that the mount face is orthogonal to an optical axis (L, L1) of the objective lens, and wherein the stage is configured to be movable in a first direction obliquely intersecting with the optical axis (L, L1) while the mount face is kept orthogonal to the optical axis (L, L1), a moving mechanism for moving the stage in the first direction obliquely intersecting with the optical axis (L, L1) and a second direction orthogonal to the first direction, a focus adjustment driving mechanism for moving the objective lens in a direction along the optical axis (L, L1), and characterized by the system (1A, 1B) further comprising a control unit configured to control, during a microscope imaging method, the moving mechanism to move the stage in the first direction and in the second direction, and to control, during the microscope imaging method, the focus adjustment driving mechanism so as to adjust a focus of the objective lens on the specimen in correspondence to the movement of the stage in the first direction, wherein, for adjusting the focus of the objective lens on the specimen, a moving direction of the objective lens is limited to the one direction along the optical axis (L, L1).