We propose a novel approach for evaluating both the stiffness and internal viscosity of a cell by using a μ-channel. The key idea comes from the fact that cell behavior in the channel can be separated into two phases; one is in the entrance area where the cell heavily deforms within a short distance, and the other is in the remaining area where the cell keeps almost constant shape. By focusing on the cell behavior in the first area, we can evaluate the internal viscosity of a cell. By focusing on the cell behavior in the second area, we can evaluate the stiffness. We conducted experiments with two different initial velocities of red blood cells, and discussed the results from the viewpoint of applicability.