This paper presents a task-oriented design method for robot kinematics based on the Grid Method, which is widely used in the finite difference method and heat transfer/fluid flow analyses. This approach drastically reduces the complexity of the whole problem and increases the efficiency compared with previous approaches. More specifically, the Grid Method with a new formulation simplifies the design to a problem of a four-design-variable unit grid, which does not require solving inverse/forward kinematics. The efficiency of the Grid Method has been confirmed through a kinematics design of a planar robot for nuclear power plants and spatial robots.