An inverter stack capable of structure modification comprising: a case having an interior space and including a main body frame and a cover, wherein the main body frame includes a front part, a rear part facing the front part, an upper part provided at the tops of the front part and the rear part, and a lower part facing the upper part, and the cover is detachably coupled to the main body frame and covers the main body frame; a circuit unit provided in the interior space; an inverter controller provided in the interior space and connected to the circuit unit to transfer a signal; and a bus bar provided in the case and connected to the circuit unit, the bus bar being electrically connected to a power supply, characterized in that the bus bar includes: a modular bus bar formed to protrude from the rear part of the main body frame and configured to pass through the cover; and an integrated bus bar provided on at least one pair of parts facing each other, among the front part, the rear part, the upper part, and the lower part, the integrated bus bar being covered with the cover, wherein the inverter stack is selectively changed to a modular structure in which the modular bus bar is connected with the power supply or an integrated structure in which the integrated bus bar is connected with the power supply, by coupling the cover to the main body frame or separating the cover from the main body frame, the cover includes: a front cover configured to cover the front part of the main body frame; a rear cover configured to cover the rear part; and a side cover configured to cover side parts on opposite sides of the front part and the rear part, and wherein the modular bus bar is connected to the circuit unit so as to be removable. a case having an interior space and including a main body frame and a cover, wherein the main body frame includes a front part, a rear part facing the front part, an upper part provided at the tops of the front part and the rear part, and a lower part facing the upper part, and the cover is detachably coupled to the main body frame and covers the main body frame; a circuit unit provided in the interior space; an inverter controller provided in the interior space and connected to the circuit unit to transfer a signal; and a bus bar provided in the case and connected to the circuit unit, the bus bar being electrically connected to a power supply, characterized in that the bus bar includes: a modular bus bar formed to protrude from the rear part of the main body frame and configured to pass through the cover; and an integrated bus bar provided on at least one pair of parts facing each other, among the front part, the rear part, the upper part, and the lower part, the integrated bus bar being covered with the cover, wherein the inverter stack is selectively changed to a modular structure in which the modular bus bar is connected with the power supply or an integrated structure in which the integrated bus bar is connected with the power supply, by coupling the cover to the main body frame or separating the cover from the main body frame, the cover includes: a front cover configured to cover the front part of the main body frame; a rear cover configured to cover the rear part; and a side cover configured to cover side parts on opposite sides of the front part and the rear part, and wherein the modular bus bar is connected to the circuit unit so as to be removable. a modular bus bar formed to protrude from the rear part of the main body frame and configured to pass through the cover; and an integrated bus bar provided on at least one pair of parts facing each other, among the front part, the rear part, the upper part, and the lower part, the integrated bus bar being covered with the cover, wherein the inverter stack is selectively changed to a modular structure in which the modular bus bar is connected with the power supply or an integrated structure in which the integrated bus bar is connected with the power supply, by coupling the cover to the main body frame or separating the cover from the main body frame, the cover includes: a front cover configured to cover the front part of the main body frame; a rear cover configured to cover the rear part; and a side cover configured to cover side parts on opposite sides of the front part and the rear part, and wherein the modular bus bar is connected to the circuit unit so as to be removable. a front cover configured to cover the front part of the main body frame; a rear cover configured to cover the rear part; and a side cover configured to cover side parts on opposite sides of the front part and the rear part, and wherein the modular bus bar is connected to the circuit unit so as to be removable.