A method of coating an exhaust gas purification catalyst filter with a predetermined amount of a coating material, the method comprising: injecting a predetermined amount of catalyst slurry into the catalyst filter from an inlet side of the filter comprising the steps of: (a) charging the catalyst slurry into a volume-defined container having a vertically movable bottom; (b) moving an upper end of the container toward a lower end of the inlet side of the catalyst filter so that the upper end of the container and the lower end of the inlet side of the catalyst filter are leveled; (c) sealing the lower end of the inlet side of the catalyst filter and the upper end of the container to be isolated from the outside; (d) moving the bottom of the container upward; (e) applying a vacuum pressure; and (f) releasing the sealing of the lower end of the inlet side of the catalyst filter and the upper end of the container so that about half of the inside of a catalyst filter channel is coated with the catalyst slurry; turning the half-coated catalyst filter upside down and performing steps (a) to (f) from an outlet side of the filter so that the remaining half of the inside of the catalyst filter channel is coated; and turning the catalyst filter upside down and blowing air from the outlet side to the inlet side of the catalyst filter. injecting a predetermined amount of catalyst slurry into the catalyst filter from an inlet side of the filter comprising the steps of: (a) charging the catalyst slurry into a volume-defined container having a vertically movable bottom; (b) moving an upper end of the container toward a lower end of the inlet side of the catalyst filter so that the upper end of the container and the lower end of the inlet side of the catalyst filter are leveled; (c) sealing the lower end of the inlet side of the catalyst filter and the upper end of the container to be isolated from the outside; (d) moving the bottom of the container upward; (e) applying a vacuum pressure; and (f) releasing the sealing of the lower end of the inlet side of the catalyst filter and the upper end of the container so that about half of the inside of a catalyst filter channel is coated with the catalyst slurry; (a) charging the catalyst slurry into a volume-defined container having a vertically movable bottom; (b) moving an upper end of the container toward a lower end of the inlet side of the catalyst filter so that the upper end of the container and the lower end of the inlet side of the catalyst filter are leveled; (c) sealing the lower end of the inlet side of the catalyst filter and the upper end of the container to be isolated from the outside; (d) moving the bottom of the container upward; (e) applying a vacuum pressure; and (f) releasing the sealing of the lower end of the inlet side of the catalyst filter and the upper end of the container so that about half of the inside of a catalyst filter channel is coated with the catalyst slurry; turning the half-coated catalyst filter upside down and performing steps (a) to (f) from an outlet side of the filter so that the remaining half of the inside of the catalyst filter channel is coated; and turning the catalyst filter upside down and blowing air from the outlet side to the inlet side of the catalyst filter.