Ionization chambers are the reference detectors for electron beam dosimetry. In this paper a dedicated radiotherapy plane parallel ionization chamber manufactured with low cost materials is presented for dosimetry in electron beams. The ionization chamber tested has a sensitive volume of 0.4 cm??. Both the collecting electrode and the guard ring were painted with a homogeneous mixture of nail polish and graphite. The dedicated ionization chamber presented a linear response with electron absorbed dose within the range 0.5 to 8.0 Gy, an increase of its response with the field size increasing, an angular dependence within ??5??, as recommended by international standards, and a polarity effect of 0.78% according to the field size. Considering the results obtained, it is possible to conclude that the plane parallel ionization chamber tested in this work presents potential use for elec - tron beam dosimetry in clinical routine.Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq)Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP)Instituto Nacional de Ci??ncia e Tecnologia (INCT)CNPq: 301335/2016-8FAPESP: 08/57863-2INCT: 573659/2008-7