A machine tool for processing a workpiece by moving a pallet attached with the workpiece and a spindle attached with a tool relative to each other, the machine tool comprising: a base, a table exchangably attached with a pallet and configured to move in a horizontal (Z-axis) direction on the base between a pallet changing position and a machining position, the table comprising a first table base having an inclined surface which is inclined with respect to the direction of movement of the table so as to face rearward and upward; an inclined rotational motion guide mounted along the inclined surface of the first table base, a second table base provided on the inclined rotational motion guide, the inclined rotational motion guide being configured to rotate the second table base about an inclination axis (Oc) which is perpendicular to the inclined surface, and a pallet attachment base configured for attachment of the pallet during use, said pallet having a workpiece mounting surface, and wherein the table is configured to orientate the workpiece mounting surface between a horizontal posture and a vertical posture via rotation of the second table base about the inclination axis (Oc), wherein the machine tool further comprises a pallet changer provided on a front of the base and configured to engage with the pallet attached to the pallet attachment base, when the table is at the pallet changing position and the workpiece mounting surface orientated at a horizontal posture, and a pallet on a pallet loading station, and a support stand for supporting the pallet changer, wherein said support stand is a bridge provided on the base so as to straddle the table in a direction vertical to the direction of movement of the table, and wherein said support stand is arranged so as to secure a space where the table slides below the pallet changer beyond the vertical axis (Ov) of the pallet changer, when the table is at the pallet changing position, wherein the pallet changer further comprises a pallet changing arm provided above the support stand and configured to engage with the pallet attached to the pallet attachment base and the pallet on the pallet loading station, and wherein the pallet changer further comprises an arm driving device provided on the support stand so as to stick out upward from the support stand, said arm driving device being configured to exchange the two pallets by moving the pallet changing arm upward and downward along the vertical axis (Ov) and rotating the pallet changing arm about the vertical axis (Ov). a base, a table exchangably attached with a pallet and configured to move in a horizontal (Z-axis) direction on the base between a pallet changing position and a machining position, the table comprising a first table base having an inclined surface which is inclined with respect to the direction of movement of the table so as to face rearward and upward; an inclined rotational motion guide mounted along the inclined surface of the first table base, a second table base provided on the inclined rotational motion guide, the inclined rotational motion guide being configured to rotate the second table base about an inclination axis (Oc) which is perpendicular to the inclined surface, and a pallet attachment base configured for attachment of the pallet during use, said pallet having a workpiece mounting surface, and wherein the table is configured to orientate the workpiece mounting surface between a horizontal posture and a vertical posture via rotation of the second table base about the inclination axis (Oc), wherein the machine tool further comprises a pallet changer provided on a front of the base and configured to engage with the pallet attached to the pallet attachment base, when the table is at the pallet changing position and the workpiece mounting surface orientated at a horizontal posture, and a pallet on a pallet loading station, and a support stand for supporting the pallet changer, wherein said support stand is a bridge provided on the base so as to straddle the table in a direction vertical to the direction of movement of the table, and wherein said support stand is arranged so as to secure a space where the table slides below the pallet changer beyond the vertical axis (Ov) of the pallet changer, when the table is at the pallet changing position, wherein the pallet changer further comprises a pallet changing arm provided above the support stand and configured to engage with the pallet attached to the pallet attachment base and the pallet on the pallet loading station, and wherein the pallet changer further comprises an arm driving device provided on the support stand so as to stick out upward from the support stand, said arm driving device being configured to exchange the two pallets by moving the pallet changing arm upward and downward along the vertical axis (Ov) and rotating the pallet changing arm about the vertical axis (Ov).