A microscope apparatus includes light source configured to generate an illuminating beam. The microscope apparatus further includes a first beam splitter configured to split the illuminating beam into a first component along a first path and a second component along a second path. The microscope apparatus further includes a movable reflector module along the second path. The microscope apparatus further includes a moving mechanism connected to the movable reflector module, wherein the moving mechanism is configured to move the movable reflector in a first direction for adjusting a length of the second path. The microscope apparatus further includes a second beam splitter configured to recombine the first component and the second component. The microscope apparatus further includes an observing device configured to receive the recombined first component and second component.