The invention relates to a tactile sensor capable of obtaining information for a plurality of degrees of freedom at each point on a surface. An optical tactile sensor is provided with a sensing part and a photographing device, the sensing part comprising a transparent elastic body and a plurality of groups of markers provided inside the elastic body, each marker group being made up of a number of colored markers, with markers making up different marker groups having different colors for each group. The elastic body has an arbitrary curved surface. The behavior of the colored markers when an object touches the curved surface of the elastic body is obtained as image information of markers by photographing device. The sensor further comprises a force vector distribution reconstructing device for reconstructing forces applied to said surface from information as to the behavior of markers that is obtained from said image information of markers.