A water treatment apparatus using a lamella structure, the water treatment apparatus comprising: a first treatment tank which includes a plurality of inclined plates and is configured to pass water subject to treatment between the inclined plates adjacent to each other; a second treatment tank which is installed at a rear end of the first treatment tank to accommodate the water subject to treatment and into which bubbles are supplied; a first discharge portion coupled to the first treatment tank to discharge a first pollutant collected at a lower side of the first treatment tank; a second discharge portion coupled to the second treatment tank to discharge a second pollutant floating at an upper side of the second treatment tank; a floating-type collecting portion configured to float on the water subject to treatment in the second treatment tank and collect the second pollutant floating at the upper side of the second treatment tank, the floating-type collecting portion including: a ring-shaped floating body configured to float on a water surface of the water subject to treatment; a tube made of metal, configured to be coupled to an inner side of the floating body to accommodate the second pollutant; and a flexible hose configured to be connected to the tube to move the second pollutant, wherein the plurality of inclined plates include positive electrode plates and negative electrode plates that are alternately arranged, the water subject to treatment passes between the positive electrode plate and the negative electrode plate, wherein the plurality of inclined plates is configured to coagulate and precipitate pollutants in the water subject to treatment so as to remove the pollutants by electro-coagulation and/or electro-oxydation, and wherein the floating body maintains an original horizontal state of the floating body without being tilted even when the water treatment apparatus is tilted. a first treatment tank which includes a plurality of inclined plates and is configured to pass water subject to treatment between the inclined plates adjacent to each other; a second treatment tank which is installed at a rear end of the first treatment tank to accommodate the water subject to treatment and into which bubbles are supplied; a first discharge portion coupled to the first treatment tank to discharge a first pollutant collected at a lower side of the first treatment tank; a second discharge portion coupled to the second treatment tank to discharge a second pollutant floating at an upper side of the second treatment tank; a floating-type collecting portion configured to float on the water subject to treatment in the second treatment tank and collect the second pollutant floating at the upper side of the second treatment tank, the floating-type collecting portion including: a ring-shaped floating body configured to float on a water surface of the water subject to treatment; a tube made of metal, configured to be coupled to an inner side of the floating body to accommodate the second pollutant; and a flexible hose configured to be connected to the tube to move the second pollutant, a ring-shaped floating body configured to float on a water surface of the water subject to treatment; a tube made of metal, configured to be coupled to an inner side of the floating body to accommodate the second pollutant; and a flexible hose configured to be connected to the tube to move the second pollutant, wherein the plurality of inclined plates include positive electrode plates and negative electrode plates that are alternately arranged, the water subject to treatment passes between the positive electrode plate and the negative electrode plate, wherein the plurality of inclined plates is configured to coagulate and precipitate pollutants in the water subject to treatment so as to remove the pollutants by electro-coagulation and/or electro-oxydation, and wherein the floating body maintains an original horizontal state of the floating body without being tilted even when the water treatment apparatus is tilted.