A print screen unit, comprising: a print screen, which has a rectangular shape, including a pattern of printing apertures, and a support frame including a first and a second pair of interface units (216, 216, 217, 217) to which the print screen is fitted and attached by a connection member engaged correspondingly with each pair of edges of the print screen, and a first to a fourth corner piece (218a-218d) which connect each of the interface units (216, 216, 217, 217) to each other, wherein the print screen includes engaging apertures provided on the edge of the print screen and the connection member includes engaging protrusions provided on a lower part of the connection member, which have rectangular shapes, at predetermined intervals along longitudinal directions thereof such that the edge of the print screen is fitted into the interface unit (216, 216, 217, 217) by the engaging apertures and the engaging protrusions being correspondingly engaged with each other, wherein the interface unit (216, 216, 217, 217) is provided with a lower side body part including a first connection slot to which each edge of the print screen is horizontally fitted, and provided with an upper side body part including a second connection slot to which the connection member standing substantially vertically is fitted, characterized in that the upper side body part includes an engaging surface provided on an inside lower end thereof by extending along a longitudinal direction of the interface unit (216, 216, 217, 217) and concave parts provided on opposite ends of an inside upper end thereof by extending along longitudinal directions of the interface unit (216, 216, 217, 217), and in that each of the corner pieces (218a-218d) is provided with a first and a second piece member (268, 270) connected orthogonally to each other such that the first and the second piece member are correspondingly and simultaneously fitted into the concave parts of each of end portions of the interface units (216, 216, 217, 217) and the engaging surface. a print screen, which has a rectangular shape, including a pattern of printing apertures, and a support frame including a first and a second pair of interface units (216, 216, 217, 217) to which the print screen is fitted and attached by a connection member engaged correspondingly with each pair of edges of the print screen, and a first to a fourth corner piece (218a-218d) which connect each of the interface units (216, 216, 217, 217) to each other, wherein the print screen includes engaging apertures provided on the edge of the print screen and the connection member includes engaging protrusions provided on a lower part of the connection member, which have rectangular shapes, at predetermined intervals along longitudinal directions thereof such that the edge of the print screen is fitted into the interface unit (216, 216, 217, 217) by the engaging apertures and the engaging protrusions being correspondingly engaged with each other, wherein the interface unit (216, 216, 217, 217) is provided with a lower side body part including a first connection slot to which each edge of the print screen is horizontally fitted, and provided with an upper side body part including a second connection slot to which the connection member standing substantially vertically is fitted, characterized in that the upper side body part includes an engaging surface provided on an inside lower end thereof by extending along a longitudinal direction of the interface unit (216, 216, 217, 217) and concave parts provided on opposite ends of an inside upper end thereof by extending along longitudinal directions of the interface unit (216, 216, 217, 217), and in that each of the corner pieces (218a-218d) is provided with a first and a second piece member (268, 270) connected orthogonally to each other such that the first and the second piece member are correspondingly and simultaneously fitted into the concave parts of each of end portions of the interface units (216, 216, 217, 217) and the engaging surface.