A camera parameter estimation apparatus 10 estimates camera parameters when an object is photographed by a camera. The camera parameter estimation apparatus 10 is provided with: a parameter calculation unit 20 configured to divide an error function representing a transformation between at least six sets of three-dimensional points relating to the object and two-dimensional points on an image that correspond to the respective three-dimensional points into a plurality of subproblems based on dependency among the camera parameters and the flatness of distribution of the three-dimensional points, and to calculate optimal solution candidates in the respective subproblems; and a parameter optimization unit 30 configured, with the optimal solution candidates as initial values, to find an optimal solution for minimizing an error obtained by the error function, and to output the found optimal solution as an optimal camera parameter.