An image formation device comprising: a frame body accommodating an image formation unit, the image formation unit configured to form an image based on an exposure signal; an upper cover part able to be rotatably opened and closed with respect to the frame body; and an exposure unit configured to generate the exposure signal based on image data, the exposure unit mounted on a lower surface of the upper cover part; wherein, the exposure unit comprises: a laser beam emitter configured to emit a laser beam corresponding to the exposure signal; a rotation polygon mirror part including a rotation polygon mirror configured to receive and deviate the laser beam; an f-theta lens configured to receive the deviated laser beam and generate a focused beam for emission; and plural reflectors (156, 157) sequentially disposed on a predetermined optical path whose start point is the f-theta lens and whose end point is a surface of a photoconductor drum in the image formation unit, and sequentially arranged according to predetermined separation distances configured to receive the focused beam and reflect the focused beam plural times along the predetermined optical path so as to cause the focused beam to arrive at the surface of the photoconductor drum, wherein, the plural reflectors (156, 157) include a forefront reflector and an end reflector, the forefront reflector configured to receive the focused beam, the end reflector configured to reflect the focused beam to the surface of the photoconductor drum; and when the upper cover part is in a closed state, a distance from the end reflector to the surface of the photoconductor drum is less than both the predetermined separation distances and a distance from the forefront reflector to the rotation polygon mirror. a frame body accommodating an image formation unit, the image formation unit configured to form an image based on an exposure signal; an upper cover part able to be rotatably opened and closed with respect to the frame body; and an exposure unit configured to generate the exposure signal based on image data, the exposure unit mounted on a lower surface of the upper cover part; wherein, the exposure unit comprises: a laser beam emitter configured to emit a laser beam corresponding to the exposure signal; a rotation polygon mirror part including a rotation polygon mirror configured to receive and deviate the laser beam; an f-theta lens configured to receive the deviated laser beam and generate a focused beam for emission; and plural reflectors (156, 157) sequentially disposed on a predetermined optical path whose start point is the f-theta lens and whose end point is a surface of a photoconductor drum in the image formation unit, and sequentially arranged according to predetermined separation distances configured to receive the focused beam and reflect the focused beam plural times along the predetermined optical path so as to cause the focused beam to arrive at the surface of the photoconductor drum, wherein, the plural reflectors (156, 157) include a forefront reflector and an end reflector, the forefront reflector configured to receive the focused beam, the end reflector configured to reflect the focused beam to the surface of the photoconductor drum; and when the upper cover part is in a closed state, a distance from the end reflector to the surface of the photoconductor drum is less than both the predetermined separation distances and a distance from the forefront reflector to the rotation polygon mirror. a laser beam emitter configured to emit a laser beam corresponding to the exposure signal; a rotation polygon mirror part including a rotation polygon mirror configured to receive and deviate the laser beam; an f-theta lens configured to receive the deviated laser beam and generate a focused beam for emission; and plural reflectors (156, 157) sequentially disposed on a predetermined optical path whose start point is the f-theta lens and whose end point is a surface of a photoconductor drum in the image formation unit, and sequentially arranged according to predetermined separation distances configured to receive the focused beam and reflect the focused beam plural times along the predetermined optical path so as to cause the focused beam to arrive at the surface of the photoconductor drum, wherein, the plural reflectors (156, 157) include a forefront reflector and an end reflector, the forefront reflector configured to receive the focused beam, the end reflector configured to reflect the focused beam to the surface of the photoconductor drum; and when the upper cover part is in a closed state, a distance from the end reflector to the surface of the photoconductor drum is less than both the predetermined separation distances and a distance from the forefront reflector to the rotation polygon mirror.