A bubble removing unit is disclosed including a body having an inner space, through which a liquid flows, in an interior thereof, a liquid introducing pipe through which the liquid is supplied to the body, a liquid discharging pipe through which the liquid, from which bubbles are removed, is discharged from the body, a bubble discharging pipe through which the bubbles are discharged from the inner space, and a rod-shaped bar situated in the inner space and a length of which extends in a lengthwise direction of the body, wherein a variable cross-section part situated between the liquid introducing pipe and the liquid discharging pipe and a cross-section of which varies along the lengthwise direction of the body is provided in the inner space of the body.