A dust collector includes a charging part (12) for charging dust with electricity and a dust collecting part (30). Each of a dust collecting electrode (40) and a high-voltage electrode (50) that constitute the dust collecting part (30) includes: a base (41, 51) with a rectangular grid structure having a large number of vent holes (46, 56) formed therein; and projections (42, 52) extending into the vent holes (56, 46) of the opposed electrode (50, 40). The dust collector collects dust by generating an electric field between the dust collecting electrode (40) and the high-voltage electrode (50).