The MEG II experiment with muon beams is dedicated to exploring the → e+ decay (Paul Scherrer Institut (PSI), Switzerland). To detect such a rare process, we need high intensity of muon beams and also a good energetic, spatial and time resolution for positrons and gamma quanta. The xenon photon detector and positron spectrometer consisting of a superconducting magnet, a cylindrical drift chamber, and two sets of pixelated timing counters are the main detector elements. At the seminar, positron detector operation in a real session, the first data received and detector upgrade will be considered.