An electric dust collector comprising: a dust collection unit to collect electrified dust particles; and a dust collection unit case (502, 2502) receiving the dust collection unit, wherein the dust collection unit comprises a plurality of films to generate an electric field and a fixing part fixing the films in the dust collection unit case (502, 2502), each of the films is formed in a shape of a band that is longer in a longitudinal direction than in a lateral direction, the films being arranged to face each other such that gaps are formed between the respective films, the fixing part comprises a gap maintenance part (560, 2560) disposed on at least one side of a group of films in the lateral direction for maintaining the gaps, the gap maintenance part (560, 2560) comprises: a base gap maintenance part disposed at one side of the group of films in the lateral direction and comprising a plurality of base vertical bars inserted into the gaps from the one side of the group of films in the lateral direction; and a roof gap maintenance part disposed at the other side of the group of films in the lateral direction and comprising a plurality of roof vertical bars inserted into the gaps from the other side of the group of films in the lateral direction, and wherein at least one of the base gap maintenance part and the roof gap maintenance part is provided in plural, wherein the base gap maintenance parts and the roof gap maintenance parts are alternately arranged to be spaced apart from each other in the longitudinal direction of the films, characterized in that: the base vertical bars and the roof vertical bars are inserted into the gaps further inward than middle portions of the films in the lateral direction; and each of the vertical bars (564, 568, 2560) is provided with protrusions (565, 569, 2569) protruding toward surfaces of the films for reducing the gaps between the films. a dust collection unit to collect electrified dust particles; and a dust collection unit case (502, 2502) receiving the dust collection unit, wherein the dust collection unit comprises a plurality of films to generate an electric field and a fixing part fixing the films in the dust collection unit case (502, 2502), each of the films is formed in a shape of a band that is longer in a longitudinal direction than in a lateral direction, the films being arranged to face each other such that gaps are formed between the respective films, the fixing part comprises a gap maintenance part (560, 2560) disposed on at least one side of a group of films in the lateral direction for maintaining the gaps, the gap maintenance part (560, 2560) comprises: a base gap maintenance part disposed at one side of the group of films in the lateral direction and comprising a plurality of base vertical bars inserted into the gaps from the one side of the group of films in the lateral direction; and a roof gap maintenance part disposed at the other side of the group of films in the lateral direction and comprising a plurality of roof vertical bars inserted into the gaps from the other side of the group of films in the lateral direction, and wherein at least one of the base gap maintenance part and the roof gap maintenance part is provided in plural, wherein the base gap maintenance parts and the roof gap maintenance parts are alternately arranged to be spaced apart from each other in the longitudinal direction of the films, a base gap maintenance part disposed at one side of the group of films in the lateral direction and comprising a plurality of base vertical bars inserted into the gaps from the one side of the group of films in the lateral direction; and a roof gap maintenance part disposed at the other side of the group of films in the lateral direction and comprising a plurality of roof vertical bars inserted into the gaps from the other side of the group of films in the lateral direction, and wherein at least one of the base gap maintenance part and the roof gap maintenance part is provided in plural, wherein the base gap maintenance parts and the roof gap maintenance parts are alternately arranged to be spaced apart from each other in the longitudinal direction of the films, the base vertical bars and the roof vertical bars are inserted into the gaps further inward than middle portions of the films in the lateral direction; and each of the vertical bars (564, 568, 2560) is provided with protrusions (565, 569, 2569) protruding toward surfaces of the films for reducing the gaps between the films.