Recently, multilegged walking robots are widely developed. For these robots to walk safely, a sole sensor with high performance is desired. In the present paper, an arrayed type tactile sensor made of flexible silicone rubber, which is based on microelectromechanical systems (MEMS) technology, was developed. This sensor was applied as a sole sensor of a legged mobile robot. By processing the force data from many sensing elements using neural networks, information of contact force, i.e., three-dimensional x, y, and z components of force vector, was able to be detected, which was confirmed by both simulation and experiment.