This e-learning course presents an aid for personnel wanting to increase their knowledge on operation and maintenance of low energy electrostatic ion accelerators and associated infrastructure.The learning objective is to provide introductory and background theoretical and practical information for the effective and safe operation and maintenance of accelerators, ion sources, plant and equipment as well as operational procedures. The course consists of five parts:The electrostatic acceleratorIon sourcesBeam transportVacuumSafety considerationsThe course is recommended for students, laboratory staff, and users of these facilities.