A gas/liquid separator, comprising: a housing comprising a first supply part and a second supply part,wherein the first supply part is disposed at an upper part of the housing and the second supply part is disposed at a lower part of the housing; a rotary shaft rotatably provided in the housing; a drive unit configured to rotate the rotary shaft; a fixed cone disposed in an interior of the housing and comprising a tilted area, the diameter of which decreases in a direction from the first supply part to the second supply part, a first through-hole, through which the rotary shaft passes, and at least one second through-hole, through which a second fluid introduced via the second supply part passes; and a rotary cone disposed in an interior of the housing so as to be spaced apart from the fixed cone and installed at the rotary shaft so as to rotate about the rotary shaft, wherein a diameter of the first through-hole is larger than a diameter of the second through-hole, wherein a number of second through-holes is larger than a number of first through-holes, wherein the second through-holes are disposed at the tilted area having a decreased diameter, wherein the plurality of second through-holes are provided in a circumference direction with respect to the rotary shaft, and a) wherein the fixed cone includes caps for enveloping at least a portion of each second through-hole and wherein each cap is extended from a surface of the fixed cone so as to have a tilt angle different from tilted area of the fixed cone, or b) wherein the fixed cone comprises a partition wall to prevent a first fluid introduced via the first supply part from being introduced into the second through-hole. a housing comprising a first supply part and a second supply part,wherein the first supply part is disposed at an upper part of the housing and the second supply part is disposed at a lower part of the housing; a rotary shaft rotatably provided in the housing; a drive unit configured to rotate the rotary shaft; a fixed cone disposed in an interior of the housing and comprising a tilted area, the diameter of which decreases in a direction from the first supply part to the second supply part, a first through-hole, through which the rotary shaft passes, and at least one second through-hole, through which a second fluid introduced via the second supply part passes; and a rotary cone disposed in an interior of the housing so as to be spaced apart from the fixed cone and installed at the rotary shaft so as to rotate about the rotary shaft, wherein a diameter of the first through-hole is larger than a diameter of the second through-hole, wherein a number of second through-holes is larger than a number of first through-holes, wherein the second through-holes are disposed at the tilted area having a decreased diameter, wherein the plurality of second through-holes are provided in a circumference direction with respect to the rotary shaft, and a) wherein the fixed cone includes caps for enveloping at least a portion of each second through-hole and wherein each cap is extended from a surface of the fixed cone so as to have a tilt angle different from tilted area of the fixed cone, or b) wherein the fixed cone comprises a partition wall to prevent a first fluid introduced via the first supply part from being introduced into the second through-hole. a) wherein the fixed cone includes caps for enveloping at least a portion of each second through-hole and wherein each cap is extended from a surface of the fixed cone so as to have a tilt angle different from tilted area of the fixed cone, or b) wherein the fixed cone comprises a partition wall to prevent a first fluid introduced via the first supply part from being introduced into the second through-hole.