A photolithography mask inspection apparatus has at least two sensors. One sensor is configured to sense light transmitted through an object to be inspected, and the other sensor senses light reflected off the object. A first optical system is arranged to expose a first portion of the object with a first light beam, and a second optical system is arranged to expose a second portion of the object, spaced form the first portion, with a second light beam. A third optical system focuses the transmitted light on to the first sensor, as well as the reflected light on to the second sensor. A defect detecting circuit is also provided to detect a defect of the object, based upon image data associated with the reflected and transmitted light.