The Mu3e experiment at PSI will search for the charged lepton flavour violating decay of an anti-muon to two positrons and an electron, with a sensitivity to branching ratios as low as 1E-16. To achieve this, the collaboration is building an extremely low mass detector that delivers excellent timing, vertex and momentum resolution for low energy electrons, whilst coping with high rates of up to 2E9 muon decays per second. The seminar will provide an overview of the physics case, the chosen detector concepts and technology and the progress towards completion of the Mu3e detector.