Provided is a gas filter, which includes an adsorptive membrane for adsorbing foreign substances contained in a gas, wherein the adsorptive membrane has a corrugated structure folded in a number of times or a structure having a plurality of projections, in order to increase a contact surface area of the gas per unit area, and wherein the adsorptive membrane includes: a support member having a plurality of first pores; and a first adsorptive member which is stacked on the support member and has a plurality of second pores formed therein and which is made by accumulating ion exchange nanofibers for adsorbing foreign substances.