Indoor air needs to be purified or sterilized to provide a healthy indoor environment, since people spend 90% or more of their time indoors (World Health Organization). Research showed that indoor air quality can be more polluted than outdoor air due to poor air ventilation, contamination by construction materials, chemicals, exposure to radon in the building and so on. Long-term exposure to unhealthy air can cause serious respiratory problems and even cancer. This research service reports on various technologies that enable indoor air purification, providing safe and comfortable environments suitable for human occupancy. It gives an overview of the indoor air purification industry, a snapshot of current and emerging technologies, the technology landscape, opportunity evaluation, and technology roadmap till 2020. Appended at the end of the report are some key patents and a list of industry participants’ contacts.