A combiner-positioning apparatus for a vehicular head-up display, the combiner-positioning apparatus comprising: a drive unit for supplying a driving force; a combiner assembly including a combiner , the combiner being projected and exposed to an outside or retracted or hidden into a slot formed in a dashboard by the driving force; a guide unit having a movement guide rail for guiding sliding movement of the combiner assembly in a vertical direction; a power transmission unit for transmitting the driving force to the combiner assembly ; wherein: the combiner assembly comprises: a lifting module vertically movable by the driving force transmitted via the power transmission unit ; and a holder connected to the lifting module and including a combiner-moving boss , the combiner-moving boss being slidably moved along the movement guide rail while the combiner is held, characterized in that the combiner-positioning apparatus comprises a slot cover configured to open and close the slot; and in that the combiner-positioning apparatus further comprises a lever , the lever having a first end connected to the slot cover and a second end connected to the combiner-moving boss , the lever is rotatable about a rotational shaft between the first end and the second end according to the movement of the lifting module , and the slot cover opens or closes the slot according to the rotation of the lever . a drive unit for supplying a driving force; a combiner assembly including a combiner , the combiner being projected and exposed to an outside or retracted or hidden into a slot formed in a dashboard by the driving force; a guide unit having a movement guide rail for guiding sliding movement of the combiner assembly in a vertical direction; a power transmission unit for transmitting the driving force to the combiner assembly ; wherein: the combiner assembly comprises: a lifting module vertically movable by the driving force transmitted via the power transmission unit ; and a holder connected to the lifting module and including a combiner-moving boss , the combiner-moving boss being slidably moved along the movement guide rail while the combiner is held, characterized in that the combiner-positioning apparatus comprises a slot cover configured to open and close the slot; and in that the combiner-positioning apparatus further comprises a lever , the lever having a first end connected to the slot cover and a second end connected to the combiner-moving boss , the lever is rotatable about a rotational shaft between the first end and the second end according to the movement of the lifting module , and the slot cover opens or closes the slot according to the rotation of the lever . a lifting module vertically movable by the driving force transmitted via the power transmission unit ; and a holder connected to the lifting module and including a combiner-moving boss , the combiner-moving boss being slidably moved along the movement guide rail while the combiner is held, characterized in that the combiner-positioning apparatus comprises a slot cover configured to open and close the slot; and in that the combiner-positioning apparatus further comprises a lever , the lever having a first end connected to the slot cover and a second end connected to the combiner-moving boss , the lever is rotatable about a rotational shaft between the first end and the second end according to the movement of the lifting module , and the slot cover opens or closes the slot according to the rotation of the lever . <EOS>