The invention relates to an electronic smoking device (10), an atomizer (26) for an electronic smoking device (10) and an electronic smoking assembly (100) comprising an electronic smoking device (10) and an atomizer (26). In order to prevent that different liquids mix within the atomizer (26), the electronic smoking device (10) comprises a lateral opening (50) for inserting and removing the atomizer (26), and a fixing element (54), and the atomizer (26) comprises a fixing section (46) to be removably fixed at the fixing element (54), such that the atomizer (26) can be easily exchanged.