A three-dimensional shaping method wherein, after a lamination step that includes several repetitions of forming a flat surface by sliding of a squeegee onto a powder layer formed by dispersion of powder and a sintering step in which the flat surface is irradiated with a laser beam or electron beam, the laminate is subjected to cutting with a cutting tool, the three-dimensional shaping method employing the following steps: 1. Setting the overall shape of the object to be shaped by a CAD/CAM system, and setting machining units that form the overall shape, wherein each of the machining units comprises a lateral periphery that is to be cut with a cutting blade on a lengthwise side section of the cutting tool, and an upper side that is to be cut with a cutting blade at the tip of the cutting tool and is surrounded by all or portions of the peripheral sides; 1. Setting a cutting allowance for each machining unit by a thickness "a" on the lateral periphery, and setting a cutting allowance by a thickness "b" on the upper side, wherein the thickness "b" is set to be greater than the thickness "a"; 2. Continuing lamination by addition of the thickness "a" in the horizontal direction on the peripheral sides of the machining unit located on the lower end, until reaching the upper side of the machining unit; 2. Continuing lamination based on the addition of 2 on the machining unit of 2 situated at upper side of the machining unit, in the region of the thickness "b" in the direction of the upper side; While machining unit is not situated at upper side of the machining unit of 2, finishing lamination based on the addition of 2 only in the machining region of 2, in a region of the thickness "b" in the direction of the upper side; 2. Cutting the cutting allowance of the thickness "a" on the peripheral sides of the machining unit of 2 and cutting the cutting allowance of the thickness "b" on the upper side; While in the region where the peripheral side in the machining unit of 2 and the peripheral sides in the machining unit of 2 are continuous, cutting the cutting allowance of the thickness "a" on both peripheral sides; 3. Continuing repetition of step 2 from the lowest machining unit to the topmost machining unit. 1. Setting the overall shape of the object to be shaped by a CAD/CAM system, and setting machining units that form the overall shape, wherein each of the machining units comprises a lateral periphery that is to be cut with a cutting blade on a lengthwise side section of the cutting tool, and an upper side that is to be cut with a cutting blade at the tip of the cutting tool and is surrounded by all or portions of the peripheral sides; 1. Setting a cutting allowance for each machining unit by a thickness "a" on the lateral periphery, and setting a cutting allowance by a thickness "b" on the upper side, wherein the thickness "b" is set to be greater than the thickness "a"; 2. Continuing lamination by addition of the thickness "a" in the horizontal direction on the peripheral sides of the machining unit located on the lower end, until reaching the upper side of the machining unit; 2. Continuing lamination based on the addition of 2 on the machining unit of 2 situated at upper side of the machining unit, in the region of the thickness "b" in the direction of the upper side; While machining unit is not situated at upper side of the machining unit of 2, finishing lamination based on the addition of 2 only in the machining region of 2, in a region of the thickness "b" in the direction of the upper side; 2. Cutting the cutting allowance of the thickness "a" on the peripheral sides of the machining unit of 2 and cutting the cutting allowance of the thickness "b" on the upper side; While in the region where the peripheral side in the machining unit of 2 and the peripheral sides in the machining unit of 2 are continuous, cutting the cutting allowance of the thickness "a" on both peripheral sides; 3. Continuing repetition of step 2 from the lowest machining unit to the topmost machining unit.