A head mount display device comprising: a housing comprising a closed front side and a back side having a pair of openings; a pair of optic modules arranged horizontally behind the front side in the pair of openings, each optic module including: a display provided in the housing; a barrel having one end arranged in the housing and an opposite end exposed outside the housing via the opening; a lens fixed to the barrel; a display frame coupled to the back side of the display, the display frame including a barrel accommodating part configured to surround a circumference of the barrel; a focus adjuster configured to adjust a distance between the barrel and the display by changing a position of the barrel in the barrel accommodating part; and a horizontal adjuster configured to guide horizontal movement of the optic module with respect to the housing; and a head fixing unit configured to fix the housing to a user's head wherein the focus adjuster and the horizontal adjuster provided in one optic module of the pair of optic modules is operable independently from the focus adjuster and the horizontal adjuster provided in the other optical module in the pair of optic modules, wherein the horizontal adjuster comprises: a coupling portion formed in the optic module, wherein the coupling portion comprises: a first coupling portion arranged at a top of the optic module and having a first fixing hole; and a second coupling portion arranged at a bottom of the optic module and having a second fixing hole, and a slide shaft having opposite ends coupled to the housing, wherein the slide shaft comprises: a first slide shaft extending horizontally through the first fixing hole and a second slide shaft extending horizontally through the second fixing hole, wherein, when the optic module is moved horizontally, the coupling portion moves along the slide shaft; wherein a vertical size of the first fixing hole is equal to a vertical size of a cross section of the first slide shaft; and wherein a vertical size of the second fixing hole is longer than a vertical size of a cross section of the second slide shaft. a housing comprising a closed front side and a back side having a pair of openings; a pair of optic modules arranged horizontally behind the front side in the pair of openings, each optic module including: a display provided in the housing; a barrel having one end arranged in the housing and an opposite end exposed outside the housing via the opening; a lens fixed to the barrel; a display frame coupled to the back side of the display, the display frame including a barrel accommodating part configured to surround a circumference of the barrel; a focus adjuster configured to adjust a distance between the barrel and the display by changing a position of the barrel in the barrel accommodating part; and a horizontal adjuster configured to guide horizontal movement of the optic module with respect to the housing; and a head fixing unit configured to fix the housing to a user's head wherein the focus adjuster and the horizontal adjuster provided in one optic module of the pair of optic modules is operable independently from the focus adjuster and the horizontal adjuster provided in the other optical module in the pair of optic modules, a display provided in the housing; a barrel having one end arranged in the housing and an opposite end exposed outside the housing via the opening; a lens fixed to the barrel; a display frame coupled to the back side of the display, the display frame including a barrel accommodating part configured to surround a circumference of the barrel; a focus adjuster configured to adjust a distance between the barrel and the display by changing a position of the barrel in the barrel accommodating part; and a horizontal adjuster configured to guide horizontal movement of the optic module with respect to the housing; and a head fixing unit configured to fix the housing to a user's head wherein the focus adjuster and the horizontal adjuster provided in one optic module of the pair of optic modules is operable independently from the focus adjuster and the horizontal adjuster provided in the other optical module in the pair of optic modules, a coupling portion formed in the optic module, wherein the coupling portion comprises: a first coupling portion arranged at a top of the optic module and having a first fixing hole; and a second coupling portion arranged at a bottom of the optic module and having a second fixing hole, and a slide shaft having opposite ends coupled to the housing, wherein the slide shaft comprises: a first slide shaft extending horizontally through the first fixing hole and a second slide shaft extending horizontally through the second fixing hole, wherein, when the optic module is moved horizontally, the coupling portion moves along the slide shaft; wherein a vertical size of the first fixing hole is equal to a vertical size of a cross section of the first slide shaft; and wherein a vertical size of the second fixing hole is longer than a vertical size of a cross section of the second slide shaft.