Metaverse refers to a world that transcends reality. Metaverse is a compound word of meta (transcendence) and universe (universe). The impact of the corona pandemic has provided an opportunity to rapidly grow the metaverse based on realistic content along with online and non-face-to-face environments. Various content and service platforms reflecting the concepts of metaverse and digital twin are rapidly spreading around the world in line with the pandemic situation. As their needs accelerate in response to the COVID-19 situation, the technology of metaverse and digital twin is attracting attention again as an indispensable condition for business, culture and art, national industry, and public services. In particular, the metaverse requires the balanced development of ecosystem components based on various advanced convergence technologies. In this paper, the concept of metaverse and digital twin, types of platforms, and development status are examined, and trends of key element technologies are investigated and analyzed. As these key element technologies, XR sensory technology, avatar technology, and other XR devices and parts were examined. Through this, we want to clearly pinpoint the direction in which the metaverse will develop through future technologies, services, and follow-up research.