1. An apparatus for estimating a pose of a mobile robot, comprising: an odometer which detects a variation in the pose of a mobile robot; a feature-processing module to extracts at least one feature from an upward image captured by the mobile robot; and a particle filter module to determines current poses and weights of a plurality of particles by applying the mobile robot pose variation detected by the odometer and the at least one feature extracted by the feature-processing module to previous poses and weights of the particles, wherein the at least one extracted feature is shared between each of the plurality of particles.